Check out our New Publishers' Select for Free Articles

Applied Catalysis A, General (v.400, #1-2)

Editorial Board (pp. co2).

Contents (pp. iii-xi).

Design of mesoporous silica thin films containing single-site photocatalysts and their applications to superhydrophilic materials by Yu Horiuchi; Hiromi Yamashita (pp. 1-8).

Display Omitted► Design of superhydrophilic mesoporous silica thin films containing single-site photocatalysts. ►Preparation of mesoporous thin films on various substrates. ► Mesopores and single-site photocatalysts enhance hydrophilicity. ► Photocatalytic decomposition of organic pollutants.This review article deals with the superhydrophilic modification on surfaces of various materials by coating with transparent mesoporous silica thin films containing single-site photocatalysts (isolated Ti-, V-, Cr-, Mo-, or W-oxide moieties). Mesoporous structures have been formed via evaporation-induced self-assembly (EISA) methods including two different surfactant removal processes. One is conventional calcination. The other is photocatalytic decomposition by photocatalysis of Ti-oxide moieties within the mesoporous silica matrix, which enables one to coat the surface with low thermal resistance effectively. After coating, the materials exhibit very high hydrophilic properties under dark conditions and photoinduced superhydrophilicity under UV-light irradiation. Among them, the W-containing mesoporous silica thin film shows the highest hydrophilic properties. These unique surface wetting properties are attributed to water adsorption properties of isolated transition metal oxide moieties and mesoporous structures having a large number of surface hydroxyl groups. Furthermore, the Ti-containing mesoporous silica thin film acts as a photocatalyst for the decomposition of oleic acid on the surface; therefore, the highly hydrophilic surface easily recovers under UV-light irradiation. These fascinating surface functionalities would contribute to practical applications.

Keywords: Superhydrophilicity; Photocatalysis; Single-site photocatalysts; Mesoporous silica thin film

Preparation of novel Au/Pt/Ag trimetallic nanoparticles and their high catalytic activity for aerobic glucose oxidation by Haijun Zhang; Naoki Toshima (pp. 9-13).

The synthesis and characterization of 1.5nm-diameter Au/Pt/Ag nanoparticles are reported. The catalytic activity for glucose oxidation of the nanoparticles is the highest among those of ever reported dispersion catalysts.Display Omitted► Highly active and durable Au/Pt/Ag trimetallic nanoparticle (TNP) catalysts. ► Preparation of the TNPs of 1.5nm in diameter by rapid injection of NaBH₄. ► Several times higher catalytic activity of the TNPs than that of Au nanoparticles. ► The highest activity for glucose oxidation among those ever reported colloidal catalysts. ► Not only a high instantaneous catalytic activity but also a high long-time stability.Au/Pt/Ag trimetallic nanoparticles (TNPs) of 1.5nm in diameter were synthesized by reduction of the corresponding ions with rapid injection of NaBH₄, and characterized by UV–vis, TEM and line EDS in HR-STEM. The catalytic activity for aerobic glucose oxidation of the TNPs is several times higher than that of Au NPs with nearly the same particle size. The alloy structured TNPs have the highest turnover frequency value for aerobic glucose oxidation among dispersed metal nanoparticles (NPs) ever reported.

Keywords: Au/Pt/Ag trimetallic nanoparticles; Aerobic glucose oxidation; Catalyst; Colloidal dispersions

Performance and regeneration studies of Pd–Ag/Al₂O₃ catalysts for the selective hydrogenation of acetylene by Axel Pachulski; Rainer Schödel; Peter Claus (pp. 14-24).

Display Omitted► Deactivation of Pd–Ag/Al₂O₃ catalysts were studied under tail end conditions of C₂H₂ hydrogenation. ► The catalyst with the highest long-term stability contains the lowest Ag amount. ► Catalyst regeneration must include a H₂ treatment.The selective hydrogenation of acetylene is one process to remove traces of acetylene from steam cracker cuts during the production of ethylene. Current disadvantages of commercially used Pd–Ag/Al₂O₃ catalysts applied in the C₂-tail end-selective hydrogenation are relative short cycle time (fast deactivation) caused by green oil formation and deposition of coke. Long-term tests were performed in a laboratory reactor under typical industrial conditions to investigate the deactivation of those catalysts. It was found that the Pd–Ag/Al₂O₃ catalyst with the highest long-term stability contains a Ag/Pd-ratio in the bulk of 0.41 and the lowest concentration of silver. This low silver amount causes a higher dilution of the palladium surface area than the higher silver amount within the investigated catalysts. This was indicated by CO chemisorption experiments, X-ray photoelectron spectroscopy (XPS), electron probe micro analysis (EPMA), X-ray fluorescence spectroscopy (XRF) and through the investigation of hydrocarbons deposited on the catalyst surface. The same catalyst sample was subsequently regenerated and tested in the laboratory reactor with respect to its long-term stability. The regenerated samples have the same long-term stability as the fresh sample if the regeneration procedure includes a hydrogen treatment.

Keywords: Acetylene hydrogenation; Ethylene; Palladium; Silver; Alumina; Egg shell catalyst; CO chemisorption; TEM; EPMA; XPS

Pt–Sn alloy phases and coke mobility over Pt–Sn/Al₂O₃ and Pt–Sn/ZnAl₂O₄ catalysts for propane dehydrogenation by Bao Khanh Vu; Myoung Bok Song; In Young Ahn; Young-Woong Suh; Dong Jin Suh; Won-Il Kim; Hyoung-Lim Koh; Young Gyo Choi; Eun Woo Shin (pp. 25-33).

Display Omitted► Pt–Sn/ZnAl₂O₄ showed much better catalytic stability than Pt–Sn/Al₂O₃. ► Pt–Sn alloys over Pt–Sn catalysts were unstable during the reaction. ► PtSn on ZnAl₂O₄ and Pt₃Sn on Al₂O₃ were dominant, respectively. ► Coke on PtSn had higher mobility than that on Pt₃Sn.Propane dehydrogenation on Pt–Sn/Al₂O₃ and Pt–Sn/ZnAl₂O₄ was performed, and the Pt–Sn/ZnAl₂O₄ catalyst showed a stronger tolerance for catalytic deactivation than the Pt–Sn/Al₂O₃ catalyst. In this study, we propose that the high catalytic stability of Pt–Sn/ZnAl₂O₄ originates from the relatively faster coke mobility from the metal surface to the support, which was proven by XPS measurement. XRD and HRTEM associated with EDX demonstrated that Pt–Sn alloy phases over the catalysts were transformed during the reaction and that the bimetallic phase transition was different according to the supports. Both PtSn and Pt₃Sn alloys were formed on the reduced Pt–Sn/Al₂O₃, while only the PtSn alloy was observed on the reduced Pt–Sn/ZnAl₂O₄. The Pt₃Sn phase was dominant over the spent Pt–Sn/Al₂O₃, whereas the PtSn phase remained unchanged over the spent Pt–Sn/ZnAl₂O₄ after reactions for 160 and 240min. The different bimetallic alloy formations and phase transitions in the Pt–Sn catalysts cause different coke mobilities.

Keywords: Propane dehydrogenation; Catalytic stability; Bimetallic Pt–Sn; Coke mobility; Al; ₂; O; ₃; ZnAl; ₂; O; ₄

Conversion of glycerol to acrolein in the presence of WO₃/TiO₂ catalysts by Arda Ulgen; Wolfgang F. Hoelderich (pp. 34-38).

Display Omitted► Dehydration of glycerol to acrolein over WO₃/TiO₂ catalysts performed with high yields. ► Influence of carrier properties was investigated. ► Cheap and stable catalyst system.Dehydration of glycerol to acrolein was performed on WO₃/TiO₂ catalysts in a continuous flow fixed bed reactor. A maximum of 85% acrolein selectivity was achieved at nearly complete conversion of glycerol using novel WO₃/TiO₂ catalysts for this particular reaction. The use of oxygen suppressed side product formation. In addition, correlations between carrier properties of titania and catalytic performance were observed. The outstanding properties of WO₃/TiO₂ catalyst systems for the dehydration of glycerol are revealed.

Keywords: Glycerol (glycerin); Acrolein; Alcohol dehydration; Solid acid; WO; ₃; /TiO; ₂; Sustainable technology

The influence of B-doping on the catalytic performance of Cu/HMS catalyst for the hydrogenation of dimethyloxalate by Anyuan Yin; Jingwen Qu; Xiaoyang Guo; Wei-Lin Dai; Kangnian Fan (pp. 39-47).

Display Omitted► An efficient copper–silica catalyst modified with B₂O₃ was prepared. ► This catalyst was applied in the hydrogenation of DMO to EG. ► The DMO conversion and EG selectivity can reach 100% and 98% under mild conditions.The influence of boron introduction on the performance of 20wt.% Cu/HMS catalysts for the catalytic hydrogenation of dimethyloxalate was systematically investigated. It is shown that the boron loading, boron source and the preparation method all have great effect on the catalytic behaviors of the catalyst. Characterization methods including N₂-physisorption, X-ray diffraction, H₂-temperature-programmed reduction, N₂O titration, NH₃ temperature-programmed desorption, and X-ray photoelectron spectroscopy were carried out to elucidate the structure evolution of the catalyst with the introduction of boron. Experimental results showed that the B₂O₃ modified catalyst prepared via the ammonia-evaporation-induced synthesis method exhibited the highest conversion and ethylene glycol selectivity because of the higher metallic copper surface area and copper dispersion. The optimum Cu/B mole ratio, which strongly affects the surface composition of the catalyst, was found to be 2/1. 100% DMO conversion and 98% EG selectivity could be obtained over the CuB/HMS(2/1) catalyst under 2.5h⁻¹ liquid hour space velocity, which is almost four times higher than that of the one without boron introduction.

Keywords: Key words; CuB/HMS catalysts; Hydrogenation; Dimethyl oxalate; Ethylene glycol

Heterogeneity of ingot of the fused iron catalyst for ammonia synthesis by Zofia Lendzion-Bieluń; Roman Jędrzejewski; Ewa Ekiert; Walerian Arabczyk (pp. 48-53).

Display Omitted► The ingot of the fused iron catalyst for ammonia synthesis is characterised with high heterogeneity. ► The distribution of promoters in the ingot is determined by the progress of crystallization. ► Aluminium is evenly distributed over the whole volume of the ingot. Other promoters shift along with the crystallization face. ► Their highest concentration is to be found in the middle part of the ingot.The research focused on changes in the structure, phase and chemical composition, activity and overheating resistance of the fused iron catalyst for ammonia synthesis in the ingot of the melted catalyst. The ingot is characterized with high heterogeneity. The distribution of promoters in the ingot is determined by the progress of crystallization. Aluminium is evenly distributed over the whole volume of the ingot. Other promoters shift along with the crystallization face. Their highest concentration is to be found in the middle part of the ingot.The content of promoters in the magnetite phase depends on the cooling rate of various parts of the ingot. When the temperature of cooling decreases, the concentration of aluminium in the magnetite also decreases while the concentration of calcium increases.Catalysts which are more slowly cooled, with a smaller amount of aluminium and a larger amount of calcium in the magnetite are less resistant to overheating.Catalysts from the upper and lower parts of the ingot, with the highest content of the magnetite phase, are more active than catalysts from the middle part with a significantly smaller portion of the magnetite phase.

Keywords: Iron catalyst; Ammonia synthesis; Promoters

Total oxidation of volatile organic compounds on Au/FeO_x catalysts supported on mesoporous SBA-15 silica by R. Bonelli; C. Lucarelli; T. Pasini; L.F. Liotta; S. Zacchini; S. Albonetti (pp. 54-60).

Display Omitted► Preparation of Au/FeO_x/SBA-15 catalysts using bi-metallic carbonyl clusters. ► Au nanoparticles anchored by highly dispersed FeOx species. ► Strong interaction between Au and FeOx resulted in higher catalytic performances.A series of Au/FeO_x/SBA-15 type materials were prepared by two methods: one conventional and one non-conventional: gold deposition-precipitation on FeO_x/SBA-15 and bimetallic carbonyl cluster deposition on SBA-15, respectively.Both chemical physical characterization and catalytic activity tests in the complete combustion of methanol show that the new preparation method of Au/FeO_x-supported catalysts leads to the anchoring of the Au by modifying the surface of SBA-15 with FeO_x species. This effect results in a considerable improvement in catalyst performance as compared to the classic preparation by deposition-precipitation of Au on SBA-15 and FeOx/SBA-15.

Keywords: Catalytic combustion; Gold/iron catalysts; Cluster-derived catalysts

Basic catalysis and catalysis assisted by basicity: FT-IR and TPD characterization of potassium-doped alumina by Tania Montanari; Lidia Castoldi; Luca Lietti; Guido Busca (pp. 61-69).

Display Omitted► A detailed characterization of catalysts constituted by potassium doped γ-Al₂O₃ is reported. ► IR spectra of adsorbed CO, CO₂ and NO_x and TPD of CO₂ and NO_x are reported. ► two levels of doping occurs. ► At 1% wt/wt loading the surface of alumina is partially neutralized. ► Only above 3% wt/wt medium-strength basic sites form.Adsorbents and catalyst supports produced by loading different amounts of potassium acetate on alumina followed by calcination are characterized using IR spectroscopy and TPD. CO, CO₂ and NO_x adsorption is studied. Two different ranges of potassium loading on alumina are found, namely light and heavy doping corresponding to 1% and more than 3% K wt/wt, respectively. Light doping results in the weak adsorption of CO₂ as bicarbonate species and NO₂ as bidentate nitrates. Heavy doping results in the adsorption of CO₂ as bidentate carbonates and NO₂ as polydentate nitrate species. Three families of exposed K⁺ ions are observed at increasing loading.

Keywords: IR spectroscopy; Basicity; CO adsorption; Potassium–alumina; NO; _x; adsorption; Carbon dioxide adsorption; K/Al; ₂; O; ₃; adsorbent

Rapid synthesis of 1-amidoalkyl-2-naphthols over sulfonic acid functionalized imidazolium salts by Mohammad Ali Zolfigol; Ardeshir Khazaei; Ahmad Reza Moosavi-Zare; Abdolkarim Zare; Vahid Khakyzadeh (pp. 70-81).

Display Omitted► Introducing two new catalysts (as ionic liquid) for organic transformations. ► Superiority of the catalysts with respect to the reported catalysts. ► Introducing an efficient new method for synthesis of 1-amidoalkyl-2-naphthols. ► Generality of the method, high yields and very short reaction times. ► Application of solvent-free conditions in the reaction.Novel sulfonic acid functionalized imidazolium salts including 3-methyl-1-sulfonic acid imidazolium chloride {[Msim]Cl} (an ionic liquid), 1,3-disulfonic acid imidazolium chloride {[Dsim]Cl} (an ionic liquid) and 3-methyl-1-sulfonic acid imidazolium tetrachloroaluminate {[Msim]AlCl₄} (a solid) efficiently catalyze one-pot multi-component condensation of β-naphthol with aromatic aldehydes and amide derivatives under solvent-free conditions to afford 1-amidoalkyl-2-naphthols in excellent yields (81–96%) and in very short reaction times (1–40min).

Keywords: Ionic liquid; Sulfonic acid functionalized imidazolium salts; β-Naphthol; 1-Amidoalkyl-2-naphthol; Solvent-free

HDS and HDN activity of (Ni,Co)Mo binary and ternary nitrides prepared by decomposition of hexamethylenetetramine complexes by Sandra Chouzier; Michel Vrinat; Tivadar Cseri; Magalie Roy-Auberger; Pavel Afanasiev (pp. 82-90).

Display Omitted► Highly dispersed Mo₂N, Co₃Mo₃N and Ni₃Mo₂N were prepared from HMTA complexes. ► Co(Ni)Mo nitrides are highly active HDN catalysts in the absence of sulfur. ► Sulfidation leads to surface segregation of MoS₂ and loss of activity. ► Soft oxidation and resulfidation allows partial recovery of CoMoS phase.Highly dispersed pure phases of binary and ternary nitrides (Co,Ni)Mo were prepared using decomposition of hexamethylenetetramine (HMTA) complexes. Their catalytic activity was evaluated in the HDS of thiophene and HDN of quinoline. Three different pre-treatment modes were applied, including direct in situ preparation of nitrides in the catalytic reactor; pre-sulfidation with hydrogen sulfide and soft oxidation in air followed by sulfidation. Pure bimetallic nitrides are highly active HDN catalysts in the absence of sulfur and show substantial synergy effect between Ni or Co and Mo. By contrast, no synergy was observed for thiophene HDS, specific surface rates for binary and ternary nitrides being similar to that of unsupported MoS₂. Transmission microscopy, XRD and XPS studies showed that MoS₂ segregation on the surface occurs during HDS reaction or sulfidation with H₂S. As a result bimetallic catalysts contained nitride particles covered with MoS₂ layers and VIII group metal sulfide crystalline particles in the subsurface layer. The introduction in the preparation sequence of an additional step of oxidation–sulfidation led to a considerable increase of HDS catalytic activity of bimetallic catalysts. Pre-sulfidation of nitrides with H₂S/H₂ mixture resulted in a drastic decrease of specific surface area (Ssp) and very low HDS activity. Soft sulfidation with thiophene under reaction conditions led to high Ssp and high HDS activity per unit of mass.

Keywords: Molybdenum; Cobalt; Nickel; Nitride; Sulfide; Hydrodesulfurizaton; Hydrodenitrogenation; Surface segregation

Trifluoromethanesulfonic acid immobilized on zirconium oxide obtained by the sol–gel method as catalyst in paraben synthesis by Marina Gorsd; Luis Pizzio; Mirta Blanco (pp. 91-98).

Display Omitted► Trifluoromethanesulfonic acid immobilized on zirconia, obtained by sol–gel and calcined at different temperatures, catalyzed paraben synthesis. ► The catalysts have strong acid sites, whose number decreased with acid content. ► Catalytic activity in propyl paraben synthesis decreased for supports calcined at higher temperature. ► Activity in paraben synthesis slightly diminished in the order propyl ethyl methyl ester.The parabens, alkylic esters of p-hydroxybenzoic acid, were synthesized using trifluoromethanesulfonic acid immobilized on zirconium oxide (zirconia) as catalyst. The oxide was obtained by the sol–gel method, using urea as a pore-forming agent. After removing urea by extraction with water, the solid was dried and then calcined at 100, 205, 310 and 425°C for 24h. Afterward, it was impregnated with trifluoromethanesulfonic acid in toluene at reflux and leached to remove the weakly adsorbed acid. Mesoporous materials were obtained, whose mean pore diameter increased with the temperature of the thermal treatment of the support, while the specific surface area and the amount of acid bonded to the support decreased. The samples are crystalline from 400°C and are thermally stable up to 250°C. The catalysts have strong acidity and the number of acid sites decreased with the acid content in the support. The catalytic activity in the synthesis of propyl paraben, expressed as moles of ester formed at 5h/mol acid in the catalyst, decreased when samples obtained from supports thermally treated at higher temperature were used. The activity also slightly diminished for the synthesis of different parabens in the order propyl>ethyl>methyl ester.

Keywords: Trifluoromethanesulfonic acid; Zirconium oxide; Sol–gel; Catalyst; Parabens

Catalytic reduction of benzaldehyde to toluene over Ni/γ-Al₂O₃ in the presence of aniline and H₂ by Shuai Liu; Xiaopeng Fan; Xilong Yan; Xiaobao Du; Ligong Chen (pp. 99-103).

Display Omitted► Hydrogenolysis of C–N bonds were instead of the direct reduction of C–O bonds. ► Application of aniline in the reduction of benzaldehyde to toluene was studied. ► The mechanism of the reduction process was proposed. ► Ni₃₀/γ-Al₂O₃ showed excellent activity for this transformation.An efficient method for the reduction of benzaldehyde to toluene over Ni₃₀/γ-Al₂O₃ in the presence of aniline and H₂ was established for the first time in this work. Toluene was obtained in the yield of 96.5% and no methyl cyclohexane was detected. The catalyst was characterized by XRD. Ni⁰ was the active sites for the hydrogenation and hydrogenolysis. Aniline played an important role during the reduction process.

Keywords: Hydrogenation; Reduction; Hydrogenolysis; Ni; ₃₀; /γ-Al; ₂; O; ₃

Effect of ceria on the MgO-γ-Al₂O₃ supported CeO₂/CuCl₂/KCl catalysts for ethane oxychlorination by Chao Li; Guangdong Zhou; Liping Wang; Shuli Dong; Jing Li; Tiexin Cheng (pp. 104-110).

Display Omitted► Three type ceria exist on catalyst: dispersed, crystallized, large particles. ► Catalyst with crystallized ceria enhanced activity of ethane oxychlorination. ► Crystallized ceria contains larger amount of capping oxygen species (O₂⁻/O⁻). ► Oxygen species accelerate oxidation of Cu⁺ to Cu²⁺ and form more weak acid sites.A series of CeO₂-doped CuCl₂-KCl/MgO-γ-Al₂O₃ catalysts were prepared and characterized by BET, XRD, H₂-TPR, FTIR-pyridine adsorption, NH₃-TPD and XPS techniques. XRD, BET and TPR results show that three types of ceria species exist on the surface of catalysts: dispersed ceria, small aggregated crystalline CeO₂ species and large ceria particles. It was found that copper-based catalysts modified with small aggregated crystalline ceria species exhibited higher conversion of ethane and selectivity to vinyl chloride compared to copper-based catalysts with dispersed ceria or large ceria particles. The promotional effects may be originated from the formation of large amount of surface capping oxygen species (O₂⁻ or O⁻) due to structural defects and electronic properties of nonstoichimetric ceria. Moreover, these surface capping oxygen species accelerate oxidation of part of Cu⁺ to Cu²⁺, which are responsible for the increase of intermediate Cl₂ species in the process of ethane oxychlorination. NH₃-TPD results show that the catalysts modified with small aggregated crystalline ceria species have a large amount of weak acidic sites on the surface, and these weak acidic sites benefit dehydrochlorination of dichloroethane. The activity tests revealed that the copper-based catalyst with cerium content x=5wt.% exhibited the highest activity due to the excellent coordination effect between ceria and copper species and the largest amount of weak acid sites for breaking C–H bonds and dehydrochlorination of dichloroethane.

Keywords: Ceria dispersion; TPR; Acidity; Ethane oxychlorination

High selectivity toward cyclohexanol in oxidation of cyclohexane using manganese aminophenylporphyrins as catalysts by Bruno Rocha Santos Lemos; Dayse CarvalhoDa-Silva; Daniel Zuim Mussi; Lucas da Silva Santos; Mariana Machado da Silva; Maria Eliza Moreira Dai de Carvalho; Júlio Santos Rebouças; Ynara Marina Idemori (pp. 111-116).

Display Omitted► Mn(III) aminophenylporphyrins catalyze selectively the cyclohexane oxidation. ► There is an exclusive formation of Cy-ol in these aminophenylporphyrin systems. ► It has been proposed that the porphyrin –NH₂ moieties may act as axial ligands.This work reports that the cyclohexane oxidation by iodosylbenzene and iodobenzene diacetate yields cyclohexanol as the sole product if catalyzed by the simple Mn(III) aminophenylporphyrins 5,10,15,20-tetrakis(2-aminophenyl)porphyrinatomanganese(III) chloride (Mn(III)(T2APP)Cl) and 5,10,15,20-tetrakis(4-aminophenyl)porphyrinatomanganese(III) chloride (Mn(III)(T4APP)Cl). This high selectivity was unmatched by other simple phenyl-substituted Mn(III) meso-tetraphenylporphyin-based catalysts (Mn(III)(T- X-PP)Cl, where X=H, 4-OMe, 4-Me, 4-CO₂Me, 2-Me), which led to a mixture of both cyclohexanol and cyclohexanone. The absence of cyclohexanone in the Mn(III)(T2APP)Cl and Mn(III)(T4APP)Cl as well as the possibility of re-use of the catalysts was investigated. An intermolecular coordination of the amino moieties in Mn(III)(T2APP)Cl and Mn(III)(T4APP)Cl is suggested to play a role in the high selectivity of these systems.

Keywords: Manganese porphyrins; Hydroxylation; Selectivity

Studies on styrene selective oxidation to benzaldehyde catalyzed by Cr-ZSM-5: Reaction parameters effects and kinetics by Clara Saux; Liliana B. Pierella (pp. 117-121).

Display Omitted► Transition metal cations modifying ZSM-5 as heterogeneous catalysts. ► Styrene selective oxidation to benzaldehyde. ► Cr-ZSM-5 presents best behavior as oxidation catalyst. ► Results confirm oxidation is first order for styrene and hydrogen peroxide. ► The estimate activation energy for styrene oxidation is 14.54kJ/mol.The selective styrene oxidation to benzaldehyde was studied over Cr-ZSM-5 zeolite which was selected after probed a series of transition metal cations (chromium, cobalt, iron, zinc, manganese and cupper) using hydrogen peroxide as oxidant agent. The effects of various reaction parameters such as reaction time, catalyst mass, styrene/hydrogen peroxide molar ratio, solvent nature and reaction temperature effect were evaluated over it. Using the initial rate method, a first order with respect to styrene and oxidant concentrations was determined. An apparent activation energy of 14.54kJ/mol was obtained.

Keywords: Cr-ZSM-5; Styrene oxidation; Benzaldehyde; Kinetic parameters

Structure and reactivity of copper iron pyrophosphate catalysts for selective oxidation of methane to formaldehyde and methanol by Róbert Polnišer; Magdaléna Štolcová; Milan Hronec; Milan Mikula (pp. 122-130).

Display Omitted► Hybrid phase Cu–Fe–pyrophosphate is efficient for methane selective oxidation. ► Single-pass yield of formaldehyde and methanol depends on structural characteristics. ► The structural modifications depend on pretreatment conditions and atomic ratio of metals. ► Enhanced interaction and cooperation between crystalline phase and nanodomains lead to a synergic effect of Fe and Cu.The structure of copper iron pyrophosphate catalysts prepared with various atomic ratios of metals and different pretreatment conditions was studied by using XRD, FT-IR, DR UV–vis and H₂-TPR techniques. The preparation methods modify the phase composition, oxidation state and reducibility of the patterns. The catalytic properties in the selective oxidation of methane to formaldehyde and methanol were examined in both, pulse and flow reactors, using O₂ and/or N₂O oxidizing agents. The oxidants used impact the onset of methane conversion, the primary oxidation products formation and the methane conversion. The highest single-pass yield of useful oxygenates (1.8%) was achieved with N₂O over the Cu/Fe≅1:2 pyrophosphate catalyst which consists mainly of the crystalline Fe^IIFe^III₂(P₂O₇)₂ and copper containing nanodomains. Enhanced interaction and cooperation between these phases leading to a synergic effect of Cu and Fe has been emphasized. The Cu^II and Fe^III species of the above structure can be reduced more easily but at similar temperatures than those in the crystalline CuFe₂(P₂O₇)₂. Pulse reaction studies indicate that the lattice oxygen of the catalyst could react with methane molecules producing formaldehyde and methanol and replenishment of the lattice oxygen by N₂O takes place rather readily and rapidly. The nature of active species, methane conversion and oxygenates selectivity remained almost unchanged during the time on stream.

Keywords: Methane selective oxidation; Formaldehyde; Methanol; Hybrid phase Cu–Fe–pyrophosphates; Cu–Fe synergism

Ring opening of cis-decalin on bifunctional Ir/- and Pt/La-X zeolite catalysts by Sandra Rabl; Andreas Haas; Dominic Santi; Cristina Flego; Marco Ferrari; Vincenzo Calemma; Jens Weitkamp (pp. 131-141).

Display Omitted► We studied the isomerization and ring opening of decalin atpH2=5.2MPa. ► The performance of Ir/La-X and Pt/La-X as catalysts was evaluated. ► Improved analyses enabled a safer quantitative analysis of open-chain decanes. ► Skeletal isomerization appears to follow the known rules of carbocation chemistry. ► The yields of open-chain decanes are higher than reported so far in the literature.Zeolite La-X was loaded with iridium or platinum by ion exchange with cationic complexes of the noble metals, their thermal decomposition in air and reduction with hydrogen. The resulting bifunctional catalysts were used for the hydroconversion of cis-decalin in a high-pressure flow-type apparatus at temperatures between 200 and 255°C and a hydrogen pressure of 5.2MPa. Both Ir/La-X and Pt/La-X showed a high tendency for skeletal isomerization of decalin. An important isomer was formed by type A rearrangement, namely spiro[4.5]decane. For a safer peak assignment of the most desired products, the open-chain decanes, n-decane was catalytically isomerized, and the iso-decanes thereby generated were co-injected into the gas chromatograph with a liquid product from the hydroconversion of decalin. Open-chain decane yields of up to 12% were achieved. The molar carbon number distributions of the hydrocracked products were M-shaped indicating mainly C–C bond cleavage of the ring opening products with one remaining naphthenic ring via carbocations and the paring reaction.

Keywords: Ring opening; Hydrodecyclization; Bifunctional catalysis; Ir/La-X zeolite; Pt/La-X zeolite; Open-chain decanes; Spiro[4.5]decane

Solvent effects on Cu₂O(111) surface properties and CO adsorption on Cu₂O(111) surface: A DFT study by Riguang Zhang; Lixia Ling; Zhong Li; Baojun Wang (pp. 142-147).

Solvent effects on Cu₂O(111) surface properties and the adsorption of CO on Cu₂O(111) in different solvents suggest that the solvent can improve the stability and the catalytic activity of the Cu₂O(111) surface.Display Omitted► Solvent effects can improve the stability of Cu₂O(111) surface. ► Solvent effects can increase the catalytic performance of Cu₂O(111) surface. ► Solvent effects are in favor of CO adsorption on Cu₂O(111) surface. ► Solvent effects are stable when the dielectric constant ɛ is no less than 32.63.Based on density functional theory, together with COSMO (conductor-like solvent model) in Dmol³, the solvent effects on both the Cu₂O(111) surface properties and the adsorption of CO on Cu₂O(111) surface have been systematically investigated. Different dielectric constants, including vacuum, liquid paraffin, methylene chloride, methanol and water, are considered. The solvent effect on Cu₂O(111) surface properties shows that the solvent favors Cu₂O(111) surface area growth. The adsorption of CO on Cu₂O(111) surface indicates that the structural parameters and adsorption energies of CO are very sensitive to the COSMO solvent model. Solvent effects can effectively improve the stability of CO adsorption on Cu₂O(111) surface and the case of C–O bond activation. The interaction of solvent molecules with Cu₂O(111) surface is compared with that of CO with Cu₂O(111). Results suggest that the solvent effect is the dominating cause for the interaction of CO with Cu₂O(111) surface in solvent, in which Cu₂O(111) shows higher catalytic activity for CO activation. But the solvent may be not the only reason promoting CO activation. These analyses give us some new insights into the understanding of solvent effects.

Keywords: Carbon monoxide; Cu; ₂; O(1; 1; 1); Adsorption; Solvent effect; Density functional theory

Dehydration of 1,2-propanediol to propionaldehyde over zeolite catalysts by Dazhi Zhang; Sami A.I. Barri; David Chadwick (pp. 148-155).

Display Omitted► 1,2-propanediol is a potential intermediate in a two-step process for conversion of glycerol to propionaldehyde.► Zeolites show high activity for 1,2-propanediol dehydration.► Medium pore size, unidirectional channel zeolites are very selective to propionaldehyde.► Selectivity to propionaldehyde over ZSM-23 and Theta-1 was >90% at 300–350°C.► Catalyst deactivation was partially mitigated by steam addition.Dehydration of 1,2-propanediol has been investigated over a range of zeolite catalysts with different pore structures and acidity. The reaction forms part of a two-step process for the conversion of glycerol to propionaldehyde. The effects of reaction temperature, concentration, space velocity, and SiO₂/Al₂O₃ ratio have been studied. The medium pore size, unidirectional channel zeolites ZSM-23 and Theta-1 showed high activity and selectivity to propionaldehyde (exceeding 90wt% at 300–350°C). Selectivity to the intermolecular dehydration product 2-ethyl-4-methyl-1,3-dioxolane was high at lower temperatures for all the zeolites, but decreased to a low value at higher temperatures and lower GHSV. The results are discussed in relation to the reaction mechanism and zeolite structures. Significant deactivation was observed for higher 1,2-propanediol partial pressures, which was partially mitigated by the addition of steam.

Keywords: 1,2 Propanediol; Dehydration; Propionaldehyde; Glycerol; Zeolite; Catalyst

Methane conversion reactions on Ni catalysts promoted with Rh: Influence of support by Alessandra F. Lucrédio; José M. Assaf; Elisabete M. Assaf (pp. 156-165).

Display Omitted► Ni catalysts supported on γ-Al₂O₃ and Mg(Al)O were prepared with and without Rh. ► The catalysts were tested in the reforming of biogas with synthetic air addition. ► Rh increased the amount of reducible Ni species and improved the dispersion of Ni⁰. ► Rh samples suffered higher C deposition due to a promotion of decomposition of CH₄.Ni catalysts supported on γ-Al₂O₃ and Mg(Al)O were prepared with and without Rh as a promoter and tested in the reforming of methane in the presence of excess methane, simulating a model biogas. The effects of adding synthetic air on the methane conversion and the formation of carbon were assessed. The catalysts were characterized by X-ray spectroscopy (EDS), surface area (BET), X-ray diffraction (XRD), Temperature-programmed reduction (TPR), X-ray absorption near-edge structure (XANES) and XPD. The results showed that in catalysts without Rh, the Ni interacts strongly with the supports, showing high reduction temperatures in TPR tests. The addition of Rh increased the amount of reducible Ni and facilitated the reduction of the species interacting strongly with the support. In the catalytic tests, the samples promoted with Rh suffered higher carbon deposition. The in situ XPD suggested that on the support γ-Al₂O₃, the presence of Rh probably led to a segregation of Ni species with time on stream, leading to carbon deposition. On the support MgAlO, the presence of Rh improved the dispersion of Ni, by reducing the Ni⁰ crystallite size, suggesting that in this case the carbon deposition was due to a favoring of CH₄ decomposition by Rh.

Keywords: Catalyst; Nickel; Hydrotalcite; Methane; Reforming

USING Fe-PILC as catalyst by B.P. Embaid; Jose G. Biomorgi; F. Gonzalez-Jimenez; M. Josefina Pérez-Zurita; Carlos E. Scott (pp. 166-170).

Display Omitted► Fe pillared clays (Fe-PILCs) were characterized by Mössbauer spectroscopy. ► After sulfidation of the Fe-PILC about half of the iron remains forming a pillar. ► The rest of the iron emerges from the pillars and forms a (Fe1−_xS) phase. ► Fe1−_xS and the iron in the pillars are active catalysts for the HDP of VOOEP.Fe pillared clays (Fe-PILCs) were synthesized and characterized by X-ray diffraction (XRD), surface area, thermogravimetric analysis (TGA) and⁵⁷Fe Mössbauer spectroscopy. Hydrodeporphyrinization (HDP) of vanadyl octaetil porphyrine (VOOEP) and hydrodesulfurization (HDS) of thiophene were used as catalytic tests. It was demonstrated that Fe-PILCs are very active catalysts for the HDP of VOOEP. After sulfidation of the Fe-PILC, some of the iron forms a bulk pyrrhotite-type iron sulfide (Fe1−_xS) phase and the Fe-PILC structure is partially destroyed by the sulfiding procedure. About half of the iron remains forming a pillar structure. Both, the segregated iron sulfide and the iron in the pillars, are active for the decomposition of the VOOEP.

Keywords: Fe pillared clays; Characterization; VOOEP hydrodeporphyrinization; Thiophene hydrodesulfurization; Mössbauer spectroscopy

Addition of olefins to acetylacetone catalyzed by cooperation of Brønsted acid site of zeolite and gold cluster by Ken-ichi Shimizu; Takumi Yamamoto; Yutaka Tai; Kazu Okumura; Atsushi Satsuma (pp. 171-175).

Display Omitted► HY zeolite-supported Au clusters act as heterogeneous catalysts for the addition of acetyl acetone to alkenes. ► Co-presence of metallic Au with smaller cluster size and the acidic OH groups of the zeolite was found to be necessary to achieve high selectivity. ► This is a rare example for the Brønsted acid and Au cooperating catalysis in organic reactions.HY zeolite-supported Au clusters (Au⁰HY) prepared by deposition–precipitation method, well characterized by XANES, EXAFS, and NH₃- and acetyl acetone-adsorption IR, were tested for addition of acetyl acetone to alkenes. Au⁰HY showed higher selectivity to the addition product than HY zeolite-supported Au(OH)₃ and Au clusters supported on NH₄⁺-exchanged Y zeolite, Al₂O₃, MgO, SiO₂, and TiO₂. Studies on the effect of Au oxidation state, Au cluster size and Brønsted acidity of zeolite on the catalytic showed that co-presence of metallic Au with smaller cluster size and the acidic OH groups of the zeolite was necessary to the selective formation of the addition product. Cooperation mechanism of the Brønsted acid sites of the zeolite and Au clusters is proposed.

Keywords: C–C coupling; Addition reaction; Gold cluster; Brønsted acids; Zeolite

Direct synthesis of well-ordered mesoporous Al-SBA-15 and its correlation with the catalytic activity by Pallavi Bhange; Deu S. Bhange; Sivaram Pradhan; Veda Ramaswamy (pp. 176-184).

Display Omitted► Al-SBA-15 samples with different Si/Al ratio were prepared by direct synthesis method. ► Catalytic activities for esterification of acetic acid and benzylation of anisole. ► Effects of Al-doping on the structure of the SBA-15 and on the catalytic performance.The synthesis of Al-SBA-15 under milder acidic conditions were made through an adjusting the molar H₂O/HCl ratio which indicate the formation of Si–O–Al linkages that lead to isomorphous substitution of Si⁴⁺ by some Al³⁺ ions. By adjusting the H₂O/HCl molar ratio, Al gets incorporated into the lattice of SBA-15, which is evidenced by XRD, N₂ adsorption, TEM,²⁹Si and²⁷Al MAS NMR spectroscopic data. Aluminium incorporated SBA-15 samples retained both structural and textural properties of SBA-15. The²⁷Al MAS NMR confirms that a large proportion of the Al is inserted into tetrahedral positions within the framework. The Al³⁺ ions could assume a tetrahedral coordination and be part of the hexagonal structure of silica in Al-SBA-15. In the present study, we have examined the effectiveness of Al-SBA-15, as an acid catalyst for the esterification of acetic acid and in benzylation of anisole. The high activity of Al-20 sample in esterification reaction has been attributed to isolated, generally tetrahedrally coordinated, framework Al species. While in benzylation of anisole, the best result was achieved with Al-5 catalyst. The selectivity for benzylanisole increases and that for dibenzylether decreases with increase in the Si/Al ratio of Al-SBA-15.

Keywords: Al-SBA-15; Esterification of acetic acid; Benzylation of anisole

Pd based membrane reactor for ultra pure hydrogen production through the dry reforming of methane. Experimental and modeling studies by L. Coronel; J.F. Múnera; E.A. Lombardo; L.M. Cornaglia (pp. 185-194).

Display Omitted► A one-dimensional model was used for the dry reforming of methane in a Pd based membrane reactor. ► The isothermal reactor used either Rh/La₂O₃ or Rh/La₂O₃–SiO₂ as catalysts. ► The kinetic equations developed for the Rh La based catalysts were employed in the MR simulation. ► The reactor model was validated by comparing the experimental results with the simulated values.A dense Pd–Ag membrane reactor (MR) with 100% hydrogen selectivity packed with either Rh/La₂O₃ or Rh/La₂O₃–SiO₂ as catalysts was used to carry out the dry reforming of methane. The membrane reactor simulation was performed using a well-known reactor model. For this purpose, we employed the equations derived from complete kinetic studies of the dry reforming of methane reaction in connection with both catalysts. In addition, we developed the kinetic equation for the reverse water gas shift reaction (RWGS). The combination of detailed kinetic studies with the measured permeation flux for the Pd–Ag membrane allowed a complete comparison between experimental and simulated operation variables. The variables studied for both catalysts were methane conversion and hydrogen permeation as a function of the sweep gas flow rate. The correlation between methane conversion enhancement and hydrogen recovery confirmed that a good prediction was obtained with this model. The performance of two reactor configurations (membrane reactor and conventional fixed-bed reactor) and both co-current and counter-current flow modes were compared. The effect of various operating variables such as permeation area, sweep gas flow rate and feed composition upon conversion, product compositions and hydrogen recovery were analyzed.

Keywords: Rh catalysts; Membrane reactor; Kinetic equations

Visible light responsive iodine-doped TiO₂ for photocatalytic reduction of CO₂ to fuels by Qianyi Zhang; Ying Li; Erik A. Ackerman; Marija Gajdardziska-Josifovska; Hailong Li (pp. 195-202).

Display Omitted► Iodine doped TiO₂ catalysts for CO₂ photoreduction with H₂O. ► Iodine doping enhances visible light absorption and electron–hole separation. ► Iodine doping affects TiO₂ phase contents and crystal size. ► High visible light activity for catalytic reduction of CO₂ to CO. ► Optimal iodine doping at 10% and 5% under visible and UV–vis irradation, respectively.Iodine-doped titanium oxide (I-TiO₂) nanoparticles that are photocatalitically responsive to visible light illumination have been synthesized by hydrothermal method. The structure and properties of I-TiO₂ nanocrystals prepared with different iodine doping levels and/or calcination temperatures were characterized by X-ray diffraction, transmission electron microscopy and diffraction, X-ray photoelectron spectroscopy, and UV–vis diffuse reflectance spectra. The three nominal iodine dopant levels (5, 10, 15wt.%) and the two lower calcination temperatures (375, 450°C) produced mixture of anatase and brookite nanocrystals, with small fraction of rutile found at 550°C. The anatase phase of TiO₂ increased in volume fraction with increased calcination temperature and iodine levels. The photocatalytic activities of the I-TiO₂ powders were investigated by photocatalytic reduction of CO₂ with H₂O under visible light ( λ>400nm) and also under UV–vis illumination. CO was found to be the major photoreduction product using both undoped and doped TiO₂. A high CO₂ reduction activity was observed for I-TiO₂ catalysts (highest CO yield equivalent to 2.4μmolg⁻¹h⁻¹) under visible light, and they also had much higher CO₂ photoreduction efficiency than undoped TiO₂ under UV–vis irradiation. I-TiO₂ calcined at 375°C has superior activity to those calcined at higher temperatures. Optimal doping levels of iodine were identified under visible and UV–vis irradiations, respectively. This is the first study that investigates nonmetal doped TiO₂ without other co-catalysts for CO₂ photoreduction to fuels under visible light.

Keywords: Photocatalysis; Solar energy conversion; TiO; ₂; Nanocomposite; CO; ₂; reduction

Effect of metal particle size on sulfur tolerance of Ni catalysts during autothermal reforming of isooctane by Joseph M. Mayne; Kevin A. Dahlberg; Thomas A. Westrich; Andrew R. Tadd; Johannes W. Schwank (pp. 203-214).

Isooctane reforming behavior was found to be dependent on the particle size of Ni. Smaller Ni particles were less active to H₂ and CO production, however, larger Ni particles were more prone to deactivation under thiophene exposure.Display Omitted► Ni catalysts designed with equal surface area but different particle size. ► ATR activity exhibits size-dependence with respect to Ni catalysts. ► Small Ni particles show poor ATR activity. ► Large Ni particles are ATR active but susceptible to sulfur poisoning.This paper describes to what extent Ni particle size affects the sulfur-tolerance of ceria-zirconia supported Ni catalysts during autothermal reforming (ATR) of isooctane. Particle size was isolated as an experimental variable by preparing catalysts with a range of Ni loadings that had nearly identical Ni surface areas. Under sulfur-free conditions, isooctane conversion and synthesis gas yield increased as the Ni particle size increased, contrary to the expectation that smaller particle sizes with lower Ni coordination would be more active. However, larger Ni particles proved to be more vulnerable to sulfur poisoning. The poor ATR activity of small Ni particles can be attributed either to a lack of sufficiently large nickel surface ensembles, or to their higher propensity to form nickel oxides under reaction conditions. This contribution suggests that, under typical ATR conditions, more highly dispersed Ni catalysts will not result in elevated sulfur tolerance.

Keywords: Nickel; Particle size; Sulfur poisoning; Autothermal reforming; Isooctane; Thiophene

Synthesis ofl-methionine stabilized nickel nanowires and their application for catalytic oxidative transfer hydrogenation of isopropanol by Nazar Hussain Kalwar; Sirajuddin; Syed Tufail H. Sherazi; Muhammad Ishaq Abro; Zulfiqar Ali Tagar; Syeda Sara Hassan; Yasmin Junejo; Manzoor Iqbal Khattak (pp. 215-220).

Display Omitted► Simple method was investigated for the fabrication of nickel nanowires (Ni NWs). ►l-methionine acted as capping as well as stabilizing agent for Ni NWs. ► Formed Ni NWs proved as catalysts for 100% conversion of isopropanol to acetone.Nickel nanowires (Ni NWs) were synthesized by the reducing action of hydrazine and stabilized by capping withl-methionine in aqueous solution. Characterization of the Ni NWs was carried out by UV–vis spectrometry, Fourier transform infra-red (FTIR) spectroscopy, Scanning Electron Microscopy (SEM) and X-ray diffractometry (XRD). Parameters like pH, concentration of reducing agent and molar ratio of Ni/l-methionine were found crucial for regulating the size of synthesized Ni NWs. The fabricated Ni NWs were employed as catalyst for catalytic oxidative dehydrogenation (transfer hydrogenation) of isopropanol (IPA) to acetone using aqueous medium in the presence of sodium borohydride (NaBH₄) as hydrogen source. The effect of parameters studied during transfer hydrogenation of IPA included the concentration of IPA, concentration of NaBH₄, time of reaction and amount of Ni NWs. The study revealed that IPA could be transformed into acetone with 100% yield in only 1min time of reaction. The catalyst was easy to recover and capable to be reused several times. The study shows that the catalytic transformation of IPA into acetone by synthesized Ni NWS in aqueous medium is environmental friendly in terms of recovery of catalyst, very fast and hence extremely economical.

Keywords: Nickel nanowires; Hydrazine monohydrate; l; -Methionine, Heterogeneous catalysis; Isopropanol; Acetone

Low temperature synthesis of cubic molybdenum carbide catalysts via pressure induced crystallographic orientation of MoO₃ precursor by G. Vitale; M.L. Frauwallner; E. Hernandez; C.E. Scott; P. Pereira-Almao (pp. 221-229).

Display Omitted► Conversion of MoO₃ to α-Mo₂C at 673K was achieved. ► Preferred orientation of MoO₃ facilitates the carburization. ► MoO₂ formation is disfavored when MoO₃ is preferentially oriented by pressure. ► XRD simulations suggests the formation of Mo vacancies in the α-Mo₂C. ► α-Mo₂C is active for the low temperature hydrogenation of toluene.Direct conversion of MoO₃ to cubic molybdenum carbides by temperature-programmed reaction (TPR) with a reacting gas mixture of H₂/toluene has been studied at 673K. We report for the first time that the MoO₃ precursor is able to produce a cubic molybdenum carbide phase which seems to have molybdenum vacancies in the cubic structure and such vacancies affect the experimental intensity ratio of the signals (111) and (200) of the X-ray powder diffraction patterns of the prepared material, this observation is backed up by simulation of the X-ray powder diffraction patterns of the defective structure and also because of the lower unit cell size of the material prepared (0.4097±0.0005nm). It is possible to increase the degree of conversion of the MoO₃ to the cubic carbide phase by pressing at 379bar the original precursor inducing preferred orientations of the crystallographic planes (020), (040) and (060) which facilitate the carburization of the oxide by precluding the formation of MoO₂ structures. Molybdenum carbides produced were found to be active for the low temperature hydrogenation of toluene.

Keywords: α-Mo; ₂; C; Vacancies; Catalysts; Toluene; Hydrogenation

Bucky paper with improved mechanical stability made from vertically aligned carbon nanotubes for desulfurization process by Adrien Deneuve; Kun Wang; Izabela Janowska; Kambiz Chizari; David Edouard; Ovidiu Ersen; Marc-Jacques Ledoux; Cuong Pham-Huu (pp. 230-237).

Display Omitted► Synthesis of carbon nanotubes (CNTs) with very high aspect ratio up to 20,000. ► Bucky paper (BP) was prepared from the high aspect ratio CNTs. ► The BP support was compared to carbon felt and activated carbon. ► BP–Fe₂O₃ catalyst exhibits high desulfurization performances.Bucky paper (BP) made from vertically aligned carbon nanotubes exhibits a high mechanical strength and flexibility owing to the high aspect ratio of the carbon nanotubes. Such macroscopic material with nanoscopic properties was efficiently used as a catalyst support in the gas-phase desulfurization reaction. The Fe₂O₃ (3wt.%) supported on BP exhibits superior stability and activity in H₂S oxidation to sulphur compared with other catalysts supported on activated charcoal and carbon felt. The high stability of the Fe₂O₃/BP catalyst was attributed to the presence of a strong active phase-support interaction which prevents the active phase sintering during operation.

Keywords: Bucky paper; Aligned carbon nanotubes; Carbonaceous catalysts; H; ₂; S

Mn-SBA15 catalysts prepared by impregnation: Influence of the manganese precursor by Hermicenda Pérez; Paloma Navarro; Juan José Delgado; Mario Montes (pp. 238-248).

Display Omitted► Textural data and STEM-HAADF technique indicates that MnO_x was deposited on the external surface and inside the porosity of SBA15. ► Crystalline phase of MnO_x supported on SBA15 depends on the precursor. ► TPR and EELS data indicate that Mn oxidation state in SBA15-NO₃ and SBA15-KMnO₄ is about +4 and +2.7–3 for SBA15-Ac. ► MnO_x crystalline phase containing Mn⁴⁺/Mn³⁺ pairs were the most active in the oxidation of ethyl acetate.The purpose of this study was to evaluate the effect of the precursors on the synthesis of MnO_x-SBA15 catalysts. The influence of the manganese phase on the activity of catalysts in the complete oxidation of ethyl acetate was also tested. SBA15 was synthesized according to a standard method reported in the literature and manganese was introduced onto the support following an incipient wetness method using three different precursors. The catalysts were characterized by N₂ adsorption, XRD, FTIR, TPR and HAADF and HRTEM microscopy. Then, they were tested in the oxidation of ethyl acetate. The results showed on one hand that the crystalline phase of deposited MnO_x depended on the precursor used for the impregnation and on the other, that the manganese oxide was deposited both on the external surface and inside the mesoporosity of the SBA15 that preserved it structure, although it lost textural properties by pore blockage. The activity of the catalysts depended on the crystalline phase, being the most active those with Mn⁴⁺/Mn³⁺ pairs.

Keywords: VOC abatement; Cryptomelane; Birnessite; Manganese oxides; SBA15

Erratum to “Effect of Pt addition to Ru–Sn/Al₂O₃ catalyst on hydrogenation of methyl laurate” [Appl. Catal. A: Gen. 397 (2011) 171–173] by Shin-ichi Taniguchi; Takahiko Makino; Hiroko Watanuki; Yu-uki Kojima; Makoto Sano; Takanori Miyake (pp. 249-249).

Sections

Personal tools

Applied Catalysis A, General (v.400, #1-2)

Sections

Personal tools

Local resources

Applied Catalysis A, General (v.400, #1-2)