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Chinese Journal of Catalysis
2016, Vol. 37, No. 11
Online: 25 November 2016


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He and coworkers in their Article on 1841–1850 reported a high photocatalytic activity and stability Ag₂S/Ag₂WO₄ composite microrod photocatalyst was fabricated by a facile sonochemical route. The produced intimate Ag₂S/Ag₂WO₄ interface between Ag₂S and Ag₂WO₄ crystal phases largely promotes the separation of photogenerated holes and electrons.

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Table of Contents for VOL.37 No.11 2016, 37 (11):  0-0.  Abstract ( 148 )   PDF (21432KB) ( 376 )

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Recent progress in CO oxidation over Pt-group-metal catalysts at low temperatures Jian Lin, Xiaodong Wang, Tao Zhang 2016, 37 (11):  1805-1813.  DOI: 10.1016/S1872-2067(16)62513-5 Abstract ( 606 )   [Full Text(HTML)] () PDF (805KB) ( 2744 )   CO oxidation is probably the most studied reaction in heterogeneous catalysis. This reaction has become a hot topic with the discovery of nanogold catalysts, which are active at low temperatures (at or below room temperature). Au catalysts are the benchmark for judging the activities of other metals in CO oxidation. Pt-group metals (PGMs) that give comparable performances are of particu-lar interest. In this mini-review, we summarize the advances in various PGM (Pt, Pd, Ir, Rh, Ru) catalysts that have high catalytic activities in low-temperature CO oxidation arising from reducible supports or the presence of OH species. The effects of the size of the metal species and the im-portance of the interface between the metal and the reducible support are covered and discussed in terms of their promotional role in CO oxidation at low temperatures.

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Recent advances in immobilized enzymes on nanocarriers Shilin Cao, Pei Xu, Yongzheng Ma, Xiaoxiao Yao, Yuan Yao, Minhua Zong, Xuehui Li, Wenyong Lou 2016, 37 (11):  1814-1823.  DOI: 10.1016/S1872-2067(16)62528-7 Abstract ( 511 )   [Full Text(HTML)] () PDF (2531KB) ( 1226 )   Recent progress in nanotechnology has provided high-performance nanomaterials for enzyme immobilization. Nanobiocatalysts combining enzymes and nanocarriers are drawing increasing attention because of their high catalytic performance, enhanced stabilities, improved en-zyme-substrate affinities, and reusabilities. Many studies have been performed to investigate the efficient use of cellulose nanocrystals, polydopamine-based nanomaterials, and synthetic polymer nanogels for enzyme immobilization. Various nanobiocatalysts are highlighted in this review, with the emphasis on the design, preparation, properties, and potential applications of nanoscale enzyme carriers and nanobiocatalysts.

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Osmium complexes in catalysis of olefin hydrogenation and isomerization Giorgio Chelucci, Gérard A. Pinna, Giansalvo Pinna, Maurizio Solinas, Barbara Sechi 2016, 37 (11):  1824-1836.  DOI: 10.1016/S1872-2067(16)62542-1 Abstract ( 428 )   [Full Text(HTML)] () PDF (779KB) ( 774 )   This review focuses on the evolution of the use of osmium complexes as catalysts in the hydrogena-tion and isomerization of olefins. Osmium systems show good catalytic activities and selectivities in the hydrogenation of olefins via both dihydrogen and transfer hydrogenation. Such systems there-fore have significant potential to become a powerful tool in organic synthesis.

Communication

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Selective arylation/annulation cascade reactions of 2-alkynylanilines with diaryliodonium salts Ying Duan, Yanliang Yang, Xiaoyu Dai, Dongmi Li 2016, 37 (11):  1837-1840.  DOI: 10.1016/S1872-2067(16)62522-6 Abstract ( 351 )   [Full Text(HTML)] () PDF (632KB) ( 705 )   An efficient Cu catalyzed selective arylation/annulation cascade reaction of 2-alkynylanilines with diaryliodonium salts was developed. This reaction was selective to N-arylation instead of C-arylation, which provides a simple synthetic method for N-aryl indoles.

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Sonochemical fabrication, characterization and enhanced photocatalytic performance of Ag2S/Ag2WO4 composite microrods Hongbo He, Shuangshuang Xue, Zhen Wu, Changlin Yu, Kai Yang, Guiming Peng, Wanqin Zhou, Dehao Li 2016, 37 (11):  1841-1850.  DOI: 10.1016/S1872-2067(16)62515-9 Abstract ( 465 )   [Full Text(HTML)] () PDF (1395KB) ( 1168 )   Ag2S/Ag2WO4 composite microrods, with lengths of 0.2-1 μm and diameters of 20-30 nm, were fabricated by a facile sonochemical route. The as-synthesized products were intensively investigat-ed by a series of physicochemical characterizations, such as N2 physical adsorption, X-ray diffrac-tion, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, diffuser reflectance spectroscopy, X-ray photoelectron spectroscopy, photolumines-cence spectroscopy and photocurrent response measurements. Ultrasonic irradiation yields an obvious improvement in the photocatalyst texture, for example, an increase in crystallinity and surface area. Moreover, sonochemically fabricated Ag2S/Ag2WO4 microrods display strong visible light absorption and a high transient photocurrent response. The produced intimate Ag2S/Ag2WO4 interface between Ag2S and Ag2WO4 crystal phases largely promotes the separation of photogener-ated holes and electrons. High photocatalytic activity and stability were obtained over Ag2S/Ag2WO4 composite microrods. The dye degradation rate constant of Ag2S/Ag2WO4 was 4.7 times and 29.8 times higher than that of bare Ag2WO4 and Ag2S, respectively.

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Tungsten carbide-reduced graphene oxide intercalation compound as co-catalyst for methanol oxidation Meiqin Shi, Wentian Zhang, Yingying Li, Youqun Chu, Chun'an Ma 2016, 37 (11):  1851-1859.  DOI: 10.1016/S1872-2067(16)62535-4 Abstract ( 377 )   [Full Text(HTML)] () PDF (828KB) ( 881 )   Highly dispersed tungsten carbide (WC) nanoparticles (NPs) sandwiched between few-layer re-duced graphene oxide (RGO) have been successfully synthesized by using thiourea as an anchoring and inducing reagent. The metatungstate ion,[H2W12O40]6-, is assembled on thiourea-modified gra-phene oxide (GO) by an impregnation method. The WC NPs, with a mean diameter of 1.5 nm, are obtained through a process whereby ammonium metatungstate first turns to WS2, which then forms an intercalation compound with RGO before growing, in situ, to WC NPs. The Pt/WC-RGO electro-catalysts are fabricated by a microwave-assisted method. The intimate contacts between Pt, WC, and RGO are confirmed by X-ray diffraction, scanning electron microscope, transmission electron microscope, and Raman spectroscopy. For methanol oxidation, the Pt/WC-RGO electrocatalyst ex-hibited an electrochemical surface area value of 246.1 m2/g Pt and a peak current density of 1364.7 mA/mg Pt, which are, respectively, 3.66 and 4.77 times greater than those of commercial Pt/C electrocatalyst (67.2 m2/g Pt, 286.0 mA/mg Pt). The excellent CO-poisoning resistance and long-term stability of the electrocatalyst are also evidenced by CO stripping, chronoamperometry, and accelerated durability testing. Because Pt/WC-RGO has higher catalytic activity compared with that of commercial Pt/C, as a result of its intercalated structure and synergistic effect, less Pt will be required for the same performance, which in turn will reduce the cost of the fuel cell. The present method is facile, efficient, and scalable for mass production of the nanomaterials.

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Electrochemical oxidation of aniline by a novel Ti/TiOxHy/Sb-SnO2 electrode Xiaoliang Li, Hao Xu, Wei Yan 2016, 37 (11):  1860-1870.  DOI: 10.1016/S1872-2067(16)62555-X Abstract ( 280 )   [Full Text(HTML)] () PDF (931KB) ( 718 )   Electrochemical oxidation of aniline in aqueous solution was investigated over a novel Ti/TiOxHy/Sb-SnO2 electrode prepared by the electrodeposition method. Scanning electron micros-copy, X-ray diffraction, and electrochemical measurements were used to characterize its morphol-ogy, crystal structure, and electrochemical properties. Removal of aniline by the Ti/TiOxHy/Sb-SnO2 electrode was investigated by ultraviolet-Visible spectroscopy and chemical oxygen demand (COD) analysis under different conditions, including current densities, initial concentrations of aniline, pH values, concentrations of chloride ions, and types of reactor. It was found that a higher current den-sity, a lower initial concentration of aniline, an acidic solution, the presence of chloride ions (0.2 wt% NaCl), and a three-dimensional (3D) reactor promoted the removal efficiency of aniline. Elec-trochemical degradation of aniline followed pseudo-first-order kinetics. The aniline (200 mL of 100 mg·L-1) and COD removal efficiencies reached 100% and 73.5%, respectively, at a current density of 20 mA·cm-2, pH of 7.0, and supporting electrolyte of 0.5 wt% Na2SO4 after 2 h electrolysis in a 3D reactor. These results show that aniline can be significantly removed on the Ti/TiOxHy/Sb-SnO2 electrode, which provides an efficient way for elimination of aniline from aqueous solution.

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Phenol photocatalytic degradation over mesoporous TUD-1-supported chromium oxide-doped titania photocatalyst Yee Khai Ooi, Leny Yuliati, Siew Ling Lee 2016, 37 (11):  1871-1881.  DOI: 10.1016/S1872-2067(16)62492-0 Abstract ( 300 )   [Full Text(HTML)] () PDF (970KB) ( 740 )   Mesoporous Technische Universiteit Delft (TUD-1)-supported chromium oxide-doped titania (Cr-TiO2) was developed as a promising photocatalyst for phenol photodegradation under visible light irradiation. Low-angle X-ray diffraction and Fourier transform infrared spectroscopy results confirmed the amorphous and mesoporous silicate framework of TUD-1 in TUD-1-supported Cr-TiO2. The mesostructure of TUD-1 was further verified via N2 adsorption-desorption analysis, which showed a type-IV isotherm with a narrow average pore size distribution of 3.9 nm and high surface area of >490 m2/g. Transmission electron microscopy analysis results indicated that TUD-1-supported Cr-TiO2 contained nanoparticles and porous channels. An increase in band gap energy was observed after loading Cr-TiO2 into TUD-1. Compared with that of unsupported Cr-TiO2, TUD-1-supported Cr-TiO2 showed higher photocatalytic activity for phenol degradation under visi-ble light irradiation. The TUD-1 supported Cr-TiO2 photocatalyst with a Si/Ti molar ratio of 30 ex-hibited the highest photodegradation of phenol (82%) of the prepared samples. The photodegrada-tion of phenol by the supported catalyst followed the Langmuir adsorption isotherm with first-order kinetics.

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Methylation of toluene with methanol over HZSM-5: A periodic density functional theory investigation Zhenhao Wen, Daqiang Yang, Fan Yang, Zhenhao Wei, Xuedong Zhu 2016, 37 (11):  1882-1890.  DOI: 10.1016/S1872-2067(16)62523-8 Abstract ( 467 )   [Full Text(HTML)] () PDF (666KB) ( 841 )   Periodic density functional theory was applied to investigate the reaction mechanism for the meth-ylation of toluene with methanol over HZSM-5. The results indicated that toluene could be methyl-ated at its para, meta, ortho and geminal positions via a concerted or stepwise pathway. For the concerted pathway, the calculated free energy barriers for the para, meta, ortho and geminal meth-ylation reactions were 167, 138, 139 and 183 kJ/mol, respectively. For the stepwise pathway, the dehydration of methanol was found to be the rate-determining step with a free energy barrier of 145 kJ/mol, whereas the free energy barriers for the methylation of toluene at its para, meta, ortho and geminal positions were 127, 105, 106 and 114 kJ/mol, respectively. Both pathways led to the formation of C8H11+ species as important intermediates, which could back-donate a proton to the zeolite framework via a reorientation process or form gaseous products through demethylation. Methane was formed via an intramolecular hydrogen transfer reaction from a ring carbon of the C8H11+ species to the carbon of the methyl group, with calculated energy barriers of 136, 132 and 134 kJ/mol for the para, meta and ortho C8H11+ species, respectively. The calculated free energy barriers for the formation of para-, meta-and ortho-xylene indicated that the formation of the pa-ra-xylene had the highest energy barrier for both pathways.

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Activity and stability of bacterial cellulase immobilized on magnetic nanoparticles Kandasamy Selvam, Muthusamy Govarthanan, Duraisamy Senbagam, Seralathan Kamala-Kannan, Balakrishnan Senthilkumar, Thangasamy Selvankumar 2016, 37 (11):  1891-1898.  DOI: 10.1016/S1872-2067(16)62487-7 Abstract ( 239 )   [Full Text(HTML)] () PDF (2010KB) ( 982 )   Magnetic nanoparticles (Fe3O4) were synthesized by co-precipitating Fe2+ and Fe3+ ions in an am-monia solution and treating under hydrothermal conditions. Cellulase was immobilized onto Fe3O4 magnetic nanoparticles via glutaraldehyde activation. Using response surface methodology and Box-Behnken design, the variables such as magnetic nanoparticle concentration, glutaraldehyde concentration, enzyme concentration, and cross linking time were optimized. The Box-Behnken design analysis showed a reasonable adjustment of the quadratic model with the experimental data. Statistical contour plots were generated to evaluate the changes in the response surface and to understand the relationship between the nanoparticles and the enzyme activity. Scanning electron microscopy, X-ray diffraction analysis, and Fourier transform infrared spectroscopy were studied to characterize size, structure, morphology, and binding of enzyme onto the nanoparticles. The stabil-ity and activity of the bound cellulase was analyzed using various parameters including pH, tem-perature, reusability, and storage stability. The immobilized cellulase was compared with free cel-lulase and it shows enhanced stability and activity.

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Polycondensation of ammonium thiocyanate into novel porous g-C3N4 nanosheets as photocatalysts for enhanced hydrogen evolution under visible light irradiation Yanjuan Cui, Yuxiong Wang, Hao Wang, Fu Cao, Fangyan Chen 2016, 37 (11):  1899-1906.  DOI: 10.1016/S1872-2067(16)62509-3 Abstract ( 416 )   [Full Text(HTML)] () PDF (1312KB) ( 962 )   Porous graphitic carbon nitride (pg-C3N4) nanosheets have been prepared through a one-step am-monia thermopolymerization method. The effects of synthetic temperature on the structural, optical and photocatalytic properties of the samples have been investigated. Characterization results show that the heptazine-based conjugate heterocyclic structure was formed over 500℃, which is at-tributed to the inhibitory effect of ammonia from the decomposition of NH4SCN. Precise nanosheet morphology and an increased pore distribution with an enlarged surface area are observed for the samples obtained under high temperatures. Optical analysis results show that the bandgap of the samples widens and photoluminescene intensity is gradually quenched as the treating temperature is increased. The results demonstrate that a higher polymerization temperature improves the nanolayer structure, porosity and migration rate of the photo-induced carriers of the samples. The pg-C3N4 nanosheets prepared at 600℃ presents the highest photocatalytic activity for hydrogen evolution from water under visible-light irradiation. This study demonstrates a novel strategy for the synthesis and optimization of polymer semiconductor nanosheets with gratifying photocatalytic performance.

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Effect of metal content on the activity and product selectivity of n-decane hydroisomerization over Ni-Pd/HY zeolite Dhanapalan Karthikeyan, Raji Atchudan, Raji Sivakumar 2016, 37 (11):  1907-1917.  DOI: 10.1016/S1872-2067(16)62507-X Abstract ( 262 )   [Full Text(HTML)] () PDF (665KB) ( 893 )   Metal-loaded zeolite catalysts were synthesized and examined in the hydroisomerization of n-decane. Specifically, zeolite Y was impregnated with 0.1 wt% Pd and varying amounts of Ni (0.1-0.5 wt%). The crystallinity of the metal-loaded catalysts was characterized by X-ray diffraction, and the average metal particle size was determined by transmission electron microscopy. The states of Pd and Ni were identified by X-ray photoelectron spectroscopy. Ammonia tempera-ture-programmed desorption analysis revealed the occurrence of ion-exchange of some of the cata-lyst acid sites with Ni2+. The reducibility of the HY zeolite-supported Pd, Ni, and Pd-Ni catalysts was studied by temperature-programmed reduction. The hydroisomerization of n-decane over the pre-pared catalyst was conducted at 200-450℃ under 1 atm. Ni addition of up to 0.3 wt% over 0.1 wt% Pd/HY enhanced the n-decane conversion and isomerization product selectivity. The improved selectivity of the mono-and dibranched isomers suggested the occurrence of a protonated cyclo-propane intermediate mechanism. However, further Ni addition above 0.3 wt% considerably re-duced the activity and isomerization selectivity. The bimetallic catalysts were more selective toward the formation of dibranched isomers, i.e., those containing a higher octane number.

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Promotional roles of ZrO2 and WO3 in V2O5-WO3/TiO2-ZrO2 catalysts for NOx reduction by NH3: Catalytic performance, morphology, and reaction mechanism Yaping Zhang, Longfei Wang, Juan Li, Huiyan Zhang, Haitao Xu, Rui Xiao, linjun Yang 2016, 37 (11):  1918-1930.  DOI: 10.1016/S1872-2067(16)62510-X Abstract ( 250 )   [Full Text(HTML)] () PDF (945KB) ( 1071 )   V2O5/TiO2-ZrO2 catalysts containing various amounts of WO3 were synthesized. The catalyst mor-phologies, catalytic performances, and reaction mechanisms in the selective catalytic reduction of NOx by NH3 were investigated using in situ diffuse-reflectance infrared Fourier-transform spectros-copy, temperature-programmed reduction (TPR), X-ray diffraction, and the Brunau-er-Emmett-Teller (BET) method. The BET surface area of the triple oxides increased with increasing ZrO2 doping but gradually decreased with increasing WO3 loading. Addition of sufficient WO3 helped to stabilize the pore structure and the combination of WO3 and ZrO2 improved dispersion of all the metal oxides. The mechanisms of reactions using V2O5-9%WO3/TiO2-ZrO2 and V2O5-9%WO3/TiO2 were compared by using either a single or mixed gas feed and various pretreatments. The results suggest that both reactions followed the Eley-Ridel mechanism; however, the dominant acid sites, which depended on the addition of WO3 or ZrO2, determined the pathways for NOx reduction, and involved[NH4+-NO-Brönsted acid site]* and[NH2-NO-Lewis acid site]* intermediates, respectively. NH3-TPR and H2-TPR showed that the metal oxides in the catalysts were not reduced by NH3 and O2 did not reoxidize the catalyst surfaces but participated in the formation of H2O and NO2.

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Use of NiO/SiO2 catalysts for toluene total oxidation: Catalytic reaction at lower temperatures and repeated regeneration Sang Wook Han, Myung-Geun Jeong, Il Hee Kim, Hyun Ook Seo, Young Dok Kim 2016, 37 (11):  1931-1940.  DOI: 10.1016/S1872-2067(16)62514-7 Abstract ( 413 )   [Full Text(HTML)] () PDF (668KB) ( 761 )   We deposited NiO via atomic layer deposition on mesoporous SiO2 particles with diameters of sev-eral hundred micrometers and a mean mesopore size of ~14 nm. NiO was deposited within the shell region of mesoporous SiO2 particles with a shell thickness of ~11 mm. We annealed the as-prepared NiO/SiO2 at 450 and 600℃, respectively. These two samples were used as catalysts for the uptake of toluene molecules and their oxidative conversion to CO2. The sample annealed at 450℃ was generally more reactive in toluene uptake and its subsequent conversion to CO2. When the NiO/SiO2 annealed at 450℃ was exposed to toluene vapor at 160℃ and then heated to 450℃, CO2 was emitted with almost no toluene desorption. We suggest that our catalysts can be used as building blocks for odor removal devices that operate below 200℃. These catalysts can be regularly regenerated at ~450℃.

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Dehydration of bio-ethanol to ethylene over iron exchanged HZSM-5 Baohui Chen, Jiazheng Lu, Lianping Wu, Zisheng Chao 2016, 37 (11):  1941-1948.  DOI: 10.1016/S1872-2067(16)62524-X Abstract ( 393 )   [Full Text(HTML)] () PDF (577KB) ( 857 )   Iron exchanged ZSM-5 with Si/Al ratio from 25 to 300 prepared by three consecutive ion exchanges was used for the dehydration of ethanol to ethylene. The iron exchanged ZSM-5 (Si/Al=25) catalyst with an iron content of 0.46 wt% gave 97%-99% yield of ethylene at 98%-99% conversion of eth-anol at 260℃ and 0.81 h-1 liquid hourly space velocity. The high performance was maintained for 60 d on-stream. X-ray diffraction, Fourier transform infrared spectroscopy of pyridine adsorption, NH3 temperature-programmed desorption and diffuse reflectance UV-vis spectroscopy were used for catalyst characterization. Ion exchange with iron decreased the total acidity of the zeolite, espe-cially the strong acid sites and Brönsted acid sites. The doped iron species were distributed over Fe-ZSM-5 as predominantly isolated Fe3+. Therefore, the catalytic performance for ethanol dehydra-tion to ethylene was improved.

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Influence of the synthesis method parameters used to prepare nickel-based catalysts on the catalytic performance for the glycerol steam reforming reaction M. A. Goula, N. D. Charisiou, K. N. Papageridis, G. Siakavelas 2016, 37 (11):  1949-1965.  DOI: 10.1016/S1872-2067(16)62518-4 Abstract ( 300 )   [Full Text(HTML)] () PDF (1160KB) ( 704 )   The influence of the synthesis method parameters used to prepare nickel-based catalysts on the catalytic performance for the glycerol steam reforming reaction was studied. A series of Al2O3-supported Ni catalysts were synthesized, with nickel loading of 8 wt%, using the incipient wetness, wet impregnation, and modified equilibrium deposition filtration methods. The catalysts' surface and bulk properties were determined by inductively coupled plasma (ICP), N2 adsorp-tion-desorption isotherms (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and temperature-programmed reduction (TPR). Used catalysts were characterized by techniques such as elemental analysis and SEM in order to deter-mine the level of carbon that was deposited and catalyst morphology. The results indicated that the synthesis method affected the textural, structural and surface properties of the catalysts, differenti-ating the dispersion and the kind of nickel species on alumina's surface. The formation of nickel aluminate phases was confirmed by the XRD and TPR analysis and the β-peak of the Ni/Al-edf cata-lyst was higher than in the other two catalysts, indicating that the nickel aluminate species of this catalyst were more reducible. Both Ni/Al-wet and Ni/Al-edf catalysts showed increasing CO2 selec-tivities and approximately constant CO selectivities for temperatures above 550℃, indicating that these catalysts successfully catalyze the water gas shift reaction. It was also confirmed that the Ni/Al-edf catalyst had the highest values for glycerol to gaseous products conversion, hydrogen yield, allyl alcohol, acetaldehyde, and acetic acid selectivities at 650℃ and the lowest carbon depo-sition of the catalysts tested. The correlation of the catalysts' structural properties, dispersion and reducibility with catalytic performance reveals that the EDF method can provide catalysts with higher specific surface area and active phase's dispersion, that are easier to reduce, more active and selective to hydrogen production, and more resistant to carbon deposition.

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Enantio-selective preparation of (S)-1-phenylethanol by a novel marine GDSL lipase MT6 with reverse stereo-selectivity Dun Deng, Yun Zhang, Aijun Sun, Yunfeng Hu 2016, 37 (11):  1966-1974.  DOI: 10.1016/S1872-2067(16)62505-6 Abstract ( 272 )   [Full Text(HTML)] () PDF (2030KB) ( 737 )   We previously functionally characterized a novel marine microbial GDSL lipase MT6 and identified that the stereo-selectivity of MT6 was opposite to that of other common lipases in trans-esterification reactions. Herein, we have investigated the use of MT6 in stereo-selective bio-catalysis through direct hydrolysis reactions. Notably, the stereo-selectivity of MT6 was also demonstrated to be opposite to that of other common lipases in hydrolysis reactions. Parameters, including temperature, organic co-solvents, pH, ionic strength, catalyst loading, substrate concen-tration, and reaction time, affecting the enzymatic resolution of racemic 1-phenylethyl acetate were further investigated, with the e.e. of the final (S)-1-Phenylethanol product and the conversion being 97% and 28.5%, respectively, after process optimization. The lengths of side chains of 1-phenylethyl esters greatly affected the stereo-selectivity and conversion during kinetic resolutions. MT6 is a novel marine microbial GDSL lipase exhibiting opposite stereo-selectivities than other common lipases in both trans-esterification reactions and hydrolysis reactions.

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Effect of electron acceptors H2O2 and O2 on the generated reactive oxygen species 1O2 and OH· in TiO2-catalyzed photocatalytic oxidation of glycerol Trin Jedsukontorn, Vissanu Meeyoo, Nagahiro Saito, Mali Hunsom 2016, 37 (11):  1975-1981.  DOI: 10.1016/S1872-2067(16)62519-6 Abstract ( 282 )   [Full Text(HTML)] () PDF (663KB) ( 1157 )   The effect of the electron acceptors H2O2 and O2 on the type of generated reactive oxygen species (ROS), and glycerol conversion and product distribution in the TiO2-catalyzed photocatalytic oxida-tion of glycerol was studied at ambient conditions. In the absence of an electron acceptor, only HO· radicals were generated by irradiated UV light and TiO2. However, in the presence of the two elec-tron acceptors, both HO· radical and 1O2 were produced by irradiated UV light and TiO2 in different concentrations that depended on the concentration of the electron acceptor. The use of H2O2 as an electron acceptor enhanced glycerol conversion more than O2. The type of generated value-added compounds depended on the concentration of the generated ROS.

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Oxidation of glycerol with H2O2 on Pb-promoted Pd/γ-Al2O3 catalysts María L. Faroppa, Juan J. Musci, María E. Chiosso, Claudia G. Caggiano, Hernán P. Bideberripe, José L. García Fierro, Guillermo J. Siri, Mónica L. Casella 2016, 37 (11):  1982-1990.  DOI: 10.1016/S1872-2067(16)62531-7 Abstract ( 344 )   [Full Text(HTML)] () PDF (3236KB) ( 804 )   A series of bimetallic Pd-Pb catalysts with a constant Pd content of 1 wt% and Pb/Pd atomic ratio from 0 to 1.6 supported on γ-Al2O3 were prepared and used for glycerol oxidation with H2O2 as the oxidizing agent at atmospheric pressure, 45℃ and pH=11. The morphology and dispersion of the catalysts were characterized by scanning electron microscopy-energy dispersive X-ray spectrosco-py (SEM-EDX) and transmission electron microscopy (TEM). The presence of an alloy phase in the bimetallic catalyst was detected by X-ray photoelectron spectroscopy (XPS). Glycerol conversion obtained with the monometallic Pd catalyst was 19%, which was increased to 100% with the addi-tion of Pb. The four bimetallic PdPb catalysts were able to oxidize glycerol to dihydroxyacetone (DIHA) and the selectivity to DIHA reached 59%, 58%, 34% and 25% for PdPb0.25, PdPb0.50, PdPb1.00 and PdPb1.60 catalysts, respectively.

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Vapor phase methylation of phenol on Fe-substituted ZrO2 catalyst Celia F. Braganza, A. V. Salker 2016, 37 (11):  1991-1996.  DOI: 10.1016/S1872-2067(16)62527-5 Abstract ( 226 )   [Full Text(HTML)] () PDF (4539KB) ( 772 )   Fe-doped ZrO2 compounds were prepared by a co-precipitation method. The compounds were characterized by X-ray diffraction, N2 adsorption-desorption, ultraviolet diffuse reflectance infrared Fourier transform spectroscopy, scanning electron microscopy-energy-dispersive X-ray spectros-copy, transmission electron microscopy, NH3 temperature-programmed desorption, X-ray photoe-lectron spectroscopy, and in situ Fourier transform infrared spectroscopy. The incorporation of Fe into ZrO2 lattice favored and effectively stabilized the formation of purely ZrO2 tetragonal phase. Subsequently, the catalytic activity of the Fe-doped ZrO2 compounds was evaluated toward vapor phase methylation of phenol. The catalytic activity was governed by Fe content and related to the Lewis acidity of the prepared catalyst.

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Efficient approach to thiazolidinones via a one-pot three-component reaction involving 2-amino-1-phenylethanone hydrochloride, aldehyde and mercaptoacetic acid Asha Vasantrao Chate, Akash Gitaram Tathe, Prajyot Jayadev Nagtilak, Sunil M. Sangle, Charansingh H. Gill 2016, 37 (11):  1997-2002.  DOI: 10.1016/S1872-2067(16)62536-6 Abstract ( 427 )   [Full Text(HTML)] () PDF (567KB) ( 863 )   A highly efficient three-component reaction has been developed for the synthesis of thiazolidinones involving the reaction of 2-amino-1-phenylethanone hydrochloride with an aromatic aldehyde and mercaptoacetic acid in the presence of diisopropylethylamine in a single pot. Critically, this reaction exhibited excellent chemoselectivity, with the nitrogen atom of the 2-amino-1-phenylethanone component reacting selectively with the aromatic aldehyde to give the corresponding Schiff base. Nucleophilic attack at the carbon of the Schiff base by the sulfur atom of mercaptoacetic, followed by a cyclocondensation reaction between the nitrogen and the carboxylic acid moiety afforded the desired thiazolidinones, which were fully characterized by spectroscopic techniques.

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Vanadium supported on graphitic carbon nitride as a heterogeneous catalyst for the direct oxidation of benzene to phenol Cheng Wang, Liya Hu, Meiyin Wang, Yuanhang Ren, Bin Yue, Heyong He 2016, 37 (11):  2003-2008.  DOI: 10.1016/S1872-2067(16)62496-8 Abstract ( 386 )   [Full Text(HTML)] () PDF (1368KB) ( 936 )   A series of graphitic carbon nitride supported vanadium catalysts (xV/g-C3N4) with different vana-dium contents (x/%) were prepared by impregnation. XRD, FT-IR, TEM, TG-DTG, nitrogen adsorp-tion and XPS characterizations were conducted which revealed a strong interaction between the vanadium species and g-C3N4 support. 8V/g-C3N4 exhibited the highest activity and showed stable recyclability in the benzene hydroxylation reaction with a benzene conversion of 24.6% and phenol selectivity of 99.2% under the optimized conditions. The excellent catalytic performance of xV/g-C3N4 was due to the integration of vanadium species with high catalytic activity and the g-C3N4 support in their interaction with the benzene substrate.

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Alcohol-treated SiO2 as the support of Ir-Re/SiO2 catalysts for glycerol hydrogenolysis Wenting Luo, Yuan Lyu, Leifeng Gong, Hong Du, Miao Jiang, Yunjie Ding 2016, 37 (11):  2009-2017.  DOI: 10.1016/S1872-2067(16)62517-2 Abstract ( 300 )   [Full Text(HTML)] () PDF (1640KB) ( 767 )   The surface of SiO2 support was pretreated by C1-C4 normal alcohols before the impregnation of iridium and rhenium precursors. These catalysts were applied in high concentration glycerol aque-ous solution hydrogenolysis. The catalysts prepared from the pretreated supports exhibited high catalytic activity because of the formation of more active sites from a high dispersion of iridium oxide and rhenium oxide. The catalysts with the support pretreated by 1-propanol showed the highest glycerol conversion of 59.5%. The supports and catalysts were characterized by FT-IR, ni-trogen adsorption, TPR, XRD, TEM, H2-chemisorption and NH3-TPD.

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NO reduction by CO over TiO2-γ-Al2O3 supported In/Ag catalyst under lean burn conditions Shuang Wu, Xuebing Li, Xiangchen Fang, Yuanyuan Sun, Jing Sun, Mingdong Zhou, Shuliang Zang 2016, 37 (11):  2018-2024.  DOI: 10.1016/S1872-2067(16)62533-0 Abstract ( 219 )   [Full Text(HTML)] () PDF (849KB) ( 869 )   TiO2/γ-Al2O3 supported In/Ag catalysts were prepared by impregnation method, and investigated for NO reduction with CO as the reducing agent under lean burn conditions. The microscopic struc-ture and surface properties of the catalysts were studied by N2 adsorption-desorption, X-ray diffrac-tion, transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible spec-troscopy, H2 temperature-programmed reduction and Fourier transform infrared spectroscopy. TiO2/γ-Al2O3 supported In/Ag is a good catalyst for the reduction of NO to N2. It displayed high dis-persion, large amounts of surface active components and high NO adsorption capacity, which gave good catalytic performance and stability for the reduction of NO with CO under lean burn condi-tions. The silver species stabilized and improved the dispersion of the indium species. The introduc-tion of TiO2 into the γ-Al2O3 support promoted NO adsorption and improved the dispersion of the indium species and silver species.

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Photocatalytic activity of TiO2 supported SiO2-Al2O3 aerogels prepared from industrial fly ash Hui-Long Wang, Hui-Ping Qi, Xiao-Na Wei, Xiao-Yu Liu, Wen-Feng Jiang 2016, 37 (11):  2025-2033.  DOI: 10.1016/S1872-2067(16)62546-9 Abstract ( 275 )   [Full Text(HTML)] () PDF (610KB) ( 974 )   A ternary composite of TiO2 and a SiO2-Al2O3 aerogel with good photocatalytic activity was prepared by a simple sol-gel method with TiO2 nanoparticles and SiO2-Al2O3 aerogels derived from industrial fly ash. The structural features of the TiO2/SiO2-Al2O3 aerogel composite were investigated by X-ray powder diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, gas adsorption measurements and diffuse reflectance UV-visible spectroscopy. The optimal conditions for photocatalytic degradation of 2-sec-butyl-4,6-dinitrophenol (DNBP), included an initial DNBP concentration of 0.167 mmol/L at pH=4.86 with a catalyst concentration of 6 g/L, under visible light irradiation for 5 h. A plausible mechanism is proposed for the photocatalytic degradation of DNBP. Our composite showed higher photocatalytic activity for DNBP degradation than that of pure TiO2. This indicates that this material can serve as an efficient photocatalyst for degradation of haz-ardous organic pollutants in wastewater.

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Selenium-catalyzed oxidative carbonylation of 2-aminobenzyl alcohol to give 1,4-dihydro-2H-3,1-benzoxazin-2-one Xiaopeng Zhang, Ping Wang, Xueli Niu, Zhengwei Li, Xuesen Fan, Guisheng Zhang 2016, 37 (11):  2034-2038.  DOI: 10.1016/S1872-2067(16)62537-8 Abstract ( 291 )   [Full Text(HTML)] () PDF (431KB) ( 754 )   An efficient, economical, and phosgene-free approach was developed for the preparation of 1,4-dihydro-2H-3,1-benzoxazin-2-one from 2-aminobenzyl alcohol. In terms of its key features, this reaction uses the cheap and recyclable non-metal selenium as a catalyst instead of the noble metal palladium; carbon monoxide as a carbonylation agent instead of virulent phosgene or one of its derivatives; and oxygen as an oxidant. The selenium-catalyzed oxidative carbonylation reaction of 2-aminobenzyl alcohol proceeded efficiently in a single pot in the presence of triethylamine to af-ford 1,4-dihydro-2H-3,1-benzoxazin-2-one in 87% yield. Furthermore, the selenium catalyst was readily recovered and recycled, affording a product yield of 80% after five cycles.