Journal of Catalysts http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Catalytic Behaviour of Mesoporous Cobalt-Aluminum Oxides for CO Oxidation Wed, 01 Oct 2014 13:20:28 +0000 http://www.hindawi.com/journals/jcat/2014/807545/ Ordered mesoporous materials are promising catalyst supports due to their uniform pore size distribution, high specific surface area and pore volume, tunable pore sizes, and long-range ordering of the pore packing. The evaporation-induced self-assembly (EISA) process was applied to synthesize mesoporous mixed oxides, which consist of cobalt ions highly dispersed in an alumina matrix. The characterization of the mesoporous mixed cobalt-aluminum oxides with cobalt loadings in the range from 5 to 15 wt% and calcination temperatures of 673, 973, and 1073 K indicates that Co2+ is homogeneously distributed in the mesoporous alumina matrix. As a function of the Co loading, different phases are present comprising poorly crystalline alumina and mixed cobalt aluminum oxides of the spinel type. The mixed cobalt-aluminum oxides were applied as catalysts in CO oxidation and turned out to be highly active. Ankur Bordoloi, Miguel Sanchez, Heshmat Noei, Stefan Kaluza, Dennis Großmann, Yuemin Wang, Wolfgang Grünert, and Martin Muhler Copyright © 2014 Ankur Bordoloi et al. All rights reserved. Hydrogen Production from the Water-Gas Shift Reaction on Iron Oxide Catalysts Thu, 25 Sep 2014 09:25:48 +0000 http://www.hindawi.com/journals/jcat/2014/612575/ Unsupported and supported iron oxide catalysts were prepared by incipient wetness impregnation method and studied in the water-gas shift reaction (WGSR) in the temperature range 350–450°C. The techniques of characterization employed were BET, X-ray diffraction, acid-base measurements by microcalorimetry and in situ diffuse reflectance infrared Fourier transform spectroscopy. MgO, TiO2, or SiO2 was added in order to (i) obtain a catalyst exempt of chromium oxide and (ii) study the effect of their acid-base properties on catalytic activity of Fe2O3. X-ray diffraction studies, and calorimetric and diffuse reflectance infrared Fourier transform measurements reveal a complete change in the physicochemical properties of the iron oxide catalyst after MgO addition due to the formation of the spinel oxide phase. These results could indicate that the MgFe2O4 phase stabilizes the reduced iron phase, preventing its sintering under realistic WGSR conditions (high H2O partial pressures). R. Bouarab, S. Bennici, C. Mirodatos, and A. Auroux Copyright © 2014 R. Bouarab et al. All rights reserved. Nanosphere of Semicrystalline Polyaniline Powder: An Effective, Versatile, and Reusable Catalyst for Hantzsch Reaction Mon, 15 Sep 2014 00:00:00 +0000 http://www.hindawi.com/journals/jcat/2014/984730/ Polyaniline salt containing 1-hydroxyethane-1,1-diphosphonic acid with nanosphere morphology in semicrystalline powder form was successfully synthesized by interfacial polymerization pathway and demonstrated as polymer based acid catalyzed in the synthesis of 1,4-dihydropyridines and polyhydroquinoline derivatives. This catalyst promotes the reaction under solvent free condition in excellent yield in 10 min with recyclability. The advantages of this methodology are the easy synthesis of polymer containing acid group catalyst in powder form having easily handlable, efficient, versatile, and reusable nature. Ravi Bolagam, Rajender Boddula, and Palaniappan Srinivasan Copyright © 2014 Ravi Bolagam et al. All rights reserved. Environmentally Benign Neem Biodiesel Synthesis Using Nano-Zn-Mg-Al Hydrotalcite as Solid Base Catalysts Thu, 21 Aug 2014 05:27:14 +0000 http://www.hindawi.com/journals/jcat/2014/326575/ Hydrotalcite, also known as aluminum-magnesium layered double hydroxide (LDH) or anionic clay, is a synthetic compound that was broadly investigated in the past decade due to its many potential applications. In this work, we present an environmentally benign process for the transesterification (methanolysis) of neem oil to fatty acid methyl esters (FAME) using Zn-Mg-Al hydrotalcites as solid base catalysts in a heterogeneous manner. The catalysts were characterized by XRD, FT-IR, TPD-CO2, and the BET surface area analysis. It is well-known that the catalytic performance of hydrotalcite is dramatically increased through the incorporation of Zn into the surface of Mg-Al hydrotalcite material. The optimized parameters, 10 : 1 methanol/oil molar ratio with 7.5 g catalysts reacted under stirring speed 450 rpm at 65°C for 4 h reaction, gave a maximum ester conversion of 90.5% for the sample with Zn-Mg-Al ratio of 3 : 3 : 1. Karthikeyan Chelladurai and Manivannan Rajamanickam Copyright © 2014 Karthikeyan Chelladurai and Manivannan Rajamanickam. All rights reserved. Synthesis of V2O5 Nanoflakes on PET Fiber as Visible-Light-Driven Photocatalysts for Degradation of RhB Dye Sun, 17 Aug 2014 12:53:17 +0000 http://www.hindawi.com/journals/jcat/2014/370696/ The visible-light-driven semiconductor photocatalysts are the current research focus techniques used to decompose organic pollutants/compounds. The photodegradation efficiency of organic compounds by photocatalyst is expected to be better compared to UV-light-driven semiconductor photocatalysts technique since the major components of our solar energy are visible light (~44%). However, as most of the previous research work has been carried out using semiconductor photocatalysts in the form of powder, extra steps and costs are needed to remove this powder from the slurry to prevent secondary pollution. In this research work, we will explain our fabrication technique of V2O5 nanoflakes by growing radially on PET fibers. By utilizing the flexibility and high surface area of polymeric fibers as novel substrate for the growth of V2O5 nanoflakes, the Rhodamine B (RhB) could be degraded under visible light irradiation. The photodegradation of RhB solution by V2O5 nanoflakes followed the 1st order kinetic with a constant rate of 0.0065 min−1. The success of this research work indicates that V2O5 nanoflakes grown on PET fibre could be possibly used as organic waste water purifier under continuous flow condition. A photodegradation mechanism of V2O5 nanostructures to degrade RhB dye is proposed based on the energy diagram. Yim-Leng Chan, Swee-Yong Pung, and Srimala Sreekantan Copyright © 2014 Yim-Leng Chan et al. All rights reserved. Biocrude Production through Pyrolysis of Used Tyres Thu, 15 May 2014 00:00:00 +0000 http://www.hindawi.com/journals/jcat/2014/386371/ A review of the pyrolysis process of used tyre as a method of producing an alternative energy source is presented in this paper. The study reports the characteristics of used tyre materials and methods of recycling, types and principles of pyrolysis, the pyrolysis products and their composition, effects of process parameters, and kinetic models applied to pyrolysis. From publications, the proximate analysis of tyre rubber shows that it is composed of about 28.6 wt.% fixed carbon, 62 wt.% volatile material, 8.5 wt.% ash, and 0.9 wt.% moisture. Elemental analysis reveals that tyre rubber has an estimated value of 82 wt.% of C, 8 wt.% of H, 0.4 wt.% of N, 1.3 wt.% of S, 2.4 wt.% of O, and 5.9 wt.% of ash. Thermogravimetry analysis confirms that the pyrolysis of used tyre at atmospheric pressure commences at 250°C and completes at 550°C. The three primary products obtained from used tyre pyrolysis are solid residue (around 36 wt.%), liquid fraction or biocrude (around 55 wt.%), and gas fraction (around 9 wt.%). Although there is variation in the value of kinetic parameters obtained by different authors from the kinetic modeling of used tyre, the process is generally accepted as a first order reaction based on Arrhenius theory. Julius I. Osayi, Sunny Iyuke, and Samuel E. Ogbeide Copyright © 2014 Julius I. Osayi et al. All rights reserved. Heterogeneous Fenton-Like Catalytic Removal of Methylene Blue Dye in Water Using Magnetic Nanocomposite (MCM-41/Magnetite) Mon, 31 Mar 2014 09:37:02 +0000 http://www.hindawi.com/journals/jcat/2014/712067/ In this work, MCM-41, magnetite (MAG), and a composite of magnetite and MCM-41 (MCM-MAG) were synthesized by a simple route for the production of active systems in the decomposition of organic waste. The materials were characterized by N2 adsorption/desorption, X-ray diffraction analysis (XRD), temperature programmed reduction (TPR), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). Our results indicated that the decolorization kinetics of the dyes were in the order of MCM-MAG > MCM-41 > magnetite. Mineralization of the dyes was monitored by total organic carbon (TOC) decrease. The dye solutions could be completely decolorized and effectively mineralized, with an average overall TOC removal 43% for a Fenton-like reaction time of 180 min. The degradation activity of the MCM-MAG was stable during four consecutive experiments, confirming their stability and reusability of the composite. The great advantage of this composite is that it may be easily magnetically recovered and reused. André E. Nogueira, Isabela A. Castro, Amanda S. Giroto, and Zuy M. Magriotis Copyright © 2014 André E. Nogueira et al. All rights reserved. Organocatalysis: Key Trends in Green Synthetic Chemistry, Challenges, Scope towards Heterogenization, and Importance from Research and Industrial Point of View Wed, 26 Mar 2014 09:39:20 +0000 http://www.hindawi.com/journals/jcat/2014/402860/ This paper purports to review catalysis, particularly the organocatalysis and its origin, key trends, challenges, examples, scope, and importance. The definition of organocatalyst corresponds to a low molecular weight organic molecule which in stoichiometric amounts catalyzes a chemical reaction. In this review, the use of the term heterogenized organocatalyst will be exclusively confined to a catalytic system containing an organic molecule immobilized onto some sort of support material and is responsible for accelerating a chemical reaction. Firstly, a brief description of the field is provided putting it in a green and sustainable perspective of chemistry. Next, research findings on the use of organocatalysts on various inorganic supports including nano(porous)materials, nanoparticles, silica, and zeolite/zeolitic materials are scrutinized in brief. Then future scope, research directions, and academic and industrial applications will be outlined. A succinct account will summarize some of the research and developments in the field. This review tries to bring many outstanding researches together and shows the vitality of the organocatalysis through several aspects. Isak Rajjak Shaikh Copyright © 2014 Isak Rajjak Shaikh. All rights reserved. Improvement the Activity and Selectivity of Fenton System in the Oxidation of Alcohols Mon, 24 Mar 2014 09:50:06 +0000 http://www.hindawi.com/journals/jcat/2014/823054/ The reactivity and selectivity of Fenton system (Fe2+/H2O2) were improved with N-hydroxyphthalimide (NHPI) as cocatalyst. The oxidation process of benzyl alcohol to benzaldehyde has been studied. The reaction catalyzed by this new Fe2+/H2O2/NHPI system can be well performed under room temperature without adding any organic solvent. Besides, this catalyst system is effective for the oxidation of different alcohols. Guoqiang Yang, Qiuxing Lin, Xingbang Hu, Youting Wu, and Zhibing Zhang Copyright © 2014 Guoqiang Yang et al. All rights reserved. Preliminary Assessment of Oxidation Pretreated Hastelloy as Hydrocarbon Steam Reforming Catalyst Mon, 24 Mar 2014 08:36:02 +0000 http://www.hindawi.com/journals/jcat/2014/210371/ The potential of oxidation pretreated Hastelloy tube as a hydrocarbon steam reforming catalyst was assessed using tetradecane, toluene, and naphthalene as model compounds. Surface characterization showed that Fe2O3, Cr2O3, MoO3, and NiO were formed on the surface of the alloy after oxidation at 1000°C for 2 hours. Catalytic evaluation showed good activity and stability with tetradecane while lower activity with increased rate of carbon formation was observed with naphthalene. S. R. de la Rama, S. Kawai, H. Yamada, and T. Tagawa Copyright © 2014 S. R. de la Rama et al. All rights reserved. Silk-Cocoon Matrix Immobilized Lipase Catalyzed Transesterification of Sunflower Oil for Production of Biodiesel Mon, 10 Feb 2014 12:17:59 +0000 http://www.hindawi.com/journals/jcat/2014/868535/ Biodiesel from sunflower oil using lipase chemically immobilized on silk-cocoon matrix in a packed-bed bioreactor was investigated. The immobilization was demonstrated by field-emission scanning electron microscopy and activity study. The lipase loading was 738.74 U (~0.01 g lipase powder)/g-lipase-immobilized matrix. The (Michaelis-Menten constant) of the free and the immobilized lipase was 451.26 μM and 257.26 μM, respectively. Low value of the immobilized lipase is attributed to the hydrophobic nature of the matrix that facilitated the substrate diffusion to the enzyme surface. The biodiesel yield of 81.62% was obtained at 48 hours reaction time, 6 : 1 methanol : oil ratio (v/v), and 30°C. The immobilized lipase showed high operational stability at 30°C. The substrate conversion was only marginally decreased till third cycle (each of 48 hours duration) of the reaction since less than even 5% of the original activity was decreased in each of the second and third cycle. The findings demonstrated the potential of the silk-cocoon as lipase immobilization matrix for industrial production of biodiesel. Sushovan Chatterjee, Dipti Yadav, Lepakshi Barbora, Pinakeswar Mahanta, and Pranab Goswami Copyright © 2014 Sushovan Chatterjee et al. All rights reserved. Emeraldine Base Form of Polyaniline Nanofibers as New, Economical, Green, and Efficient Catalyst for Synthesis of Z-Aldoximes Thu, 06 Feb 2014 13:37:21 +0000 http://www.hindawi.com/journals/jcat/2014/515428/ A facile, clean, economical, efficient, and green process was developed for the preparation of Z-aldoximes at room temperature under solvent-free condition using emeraldine base form of polyaniline as novel catalyst. In this methodology, PANI base absorbed the by-product of HCl (polluting chemical) from hydroxylamine hydrochloride and converted to polyaniline-hydrochloride salt (PANI-HCl salt). This PANI-HCl salt could be easily recovered and used in new attempts without any purification in many areas such as catalyst, electrical and electronics applications meant for conducting polymers. As far as our knowledge is concerned, emeraldine base as catalyst in organic synthesis for the first time. Rajender Boddula and Palaniappan Srinivasan Copyright © 2014 Rajender Boddula and Palaniappan Srinivasan. All rights reserved. Supported TiO2 on Borosilicate Glass Plates for Efficient Photocatalytic Degradation of Fenamiphos Wed, 15 Jan 2014 16:05:40 +0000 http://www.hindawi.com/journals/jcat/2014/413693/ Supported titanium dioxide (TiO2) was investigated for the photodegradation of the insecticide fenamiphos in water. The photocatalyst was immobilised on borosilicate glass plates and the kinetics of degradation were studied in a stirred tank reactor under UV irradiation. Two types of TiO2, for example, Millennium PC500 (100% anatase) and Degussa P25 (80% anatase, 20% rutile), were used. Their activities have been based on the rates of insecticide disappearance. Experiments were investigated to evaluate the effect of pH and initial concentrations of fenamiphos as well as catalyst doses on the photocatalytic degradation of fenamiphos. Kinetic parameters were experimentally determined and an apparent first-order kinetic was observed. For photolysis process of fenamiphos, two photoproducts were identified and characterized using high performance liquid chromatography/mass spectrometry (HPLC/MS). The plausible mechanism of photolysis involved is the oxidation of sulfonamide group. In presence of photocatalyst TiO2, photodegradation was observed. Under identical conditions, Degussa P25 shows higher photocatalytic activity in regard to PC500 Millennium and complete degradation was observed after 180 min. A. El Yadini, H. Saufi, P. S. M. Dunlop, J. Anthony Byrne, M. El Azzouzi, and S. El Hajjaji Copyright © 2014 A. El Yadini et al. All rights reserved. Preparation of Mesoporous SiO2-Pillared Lamellar Titanoniobate Catalysts for Bioethanol Dehydration Thu, 09 Jan 2014 16:40:57 +0000 http://www.hindawi.com/journals/jcat/2014/869472/ The lamellar perovskite K0,8Ti0,8Nb1,2O5 was prepared by solid state reaction, and its protonic form was used in a sequence of intercalation steps with n-butylamine, cetyltrimethylammonium bromide (CTABr), and tetraethyl orthosilicate (TEOS). After calcination, a high surface area, mesoporous SiO2-pillared titanoniobate, was obtained. The samples were characterized by XRD, EDX, TG-DTG, N2 adsorption isotherms, and NH3-TPD. The pillarization procedure affected the textural properties, the amount, and strength distribution of acid sites. The influence of the pillarization procedure on the catalytic properties of the lamellar titanoniobates was investigated on ethanol dehydration. High ethanol conversions and ethylene yields (>90%) were obtained in the presence of the SiO2-pillared titanoniobate catalyst, at 350–450°C. Olivalter Pergentino, Marina M. de Brito, Heloysa M. C. Andrade, and Artur J. S. Mascarenhas Copyright © 2014 Olivalter Pergentino et al. All rights reserved. Ceric Ion Loaded MCM-41 Catalyzed Synthesis of Substituted Mono- and Bis-dihydropyrimidin-2(1H)-ones Sat, 28 Dec 2013 18:27:21 +0000 http://www.hindawi.com/journals/jcat/2013/819184/ An effective one-pot three-component reaction of aromatic aldehydes with 1,3-diketone and urea or thiourea under solvent-free condition leads to the formation of mono- and bis-dihydropyrimidin-2-(1H)-ones using Ce-MCM-41 as a recyclable solid acid catalyst. This method has several advantages like simple and easy work-up with shorter reaction time, reusability of catalyst, and high yields of Biginelli products. Pullar Vadivel, Rathinam Ramesh, and Appaswami Lalitha Copyright © 2013 Pullar Vadivel et al. All rights reserved. Regioselective Thiocyanation of Aromatic and Heteroaromatic Compounds Using [2-(Sulfooxy)ethyl]sulfamic Acid as an Efficient, Recyclable Organocatalyst and Novel Difunctional Brønsted Acid Sun, 08 Dec 2013 09:41:49 +0000 http://www.hindawi.com/journals/jcat/2013/723903/ A green and simple procedure for the thiocyanation of aromatic and heteroaromatic compounds is described. [2-(Sulfooxy)ethyl]sulfamic acid (SESA) (supported on silica) is easily produced by addition of chlorosulfonic acid to 2-aminoethanol and this catalyst is applied as an efficient, reusable, and heterogeneous catalyst for the thiocyanation of heterocycles, substituted anilines (electron-rich and electron-deficient), and N,N-disubstituted aromatic amines using hydrogen peroxide in the water : ethanol as a solvent at room temperature. The catalyst can be easily recovered and reused for five reaction cycles without considerable loss of activity. Sami Sajjadifar, Saaid Karimian, Hadi Noorizadeh, and Hojat Veisi Copyright © 2013 Sami Sajjadifar et al. All rights reserved. Heterogeneous Tin Catalysts Applied to the Esterification and Transesterification Reactions Wed, 20 Nov 2013 10:53:49 +0000 http://www.hindawi.com/journals/jcat/2013/510509/ The interest in the development of efficient and environmentally benign catalysts for esters synthesis has increased exponentially, mainly due to the demand for biodiesel. In general, fatty esters are used as bioadditive, cosmetic ingredients, polymers, and, more recently, biofuel. Nevertheless, most of the production processes use nonrecyclable and homogenous alkaline catalysts, which results in the reactors corrosion, large generation of effluents, and residues on the steps of separation and catalyst neutralization. Heterogeneous acid catalysts can answer these demands and are an environmentally benign alternative extensively explored. Remarkably, solid acid catalysts based on tin have been shown highly attractive for the biodiesel production, mainly via FFA esterification reactions. This review describes important features related to be the synthesis, stability to, and activity of heterogeneous tin catalysts in biodiesel production reactions. Márcio José da Silva and Abiney Lemos Cardoso Copyright © 2013 Márcio José da Silva and Abiney Lemos Cardoso. All rights reserved. Highly Dispersed in Porous Silica for CO Hydrogenation Thu, 24 Oct 2013 09:09:45 +0000 http://www.hindawi.com/journals/jcat/2013/725970/ A facile method has been developed to prepare highly dispersed in porous silica. By utilizing C atoms in methyl modified silica supports, was obtained via insitu carburization. The obtained samples exhibited high activity for CO hydrogenation. Minglin Xiang and Juan Zou Copyright © 2013 Minglin Xiang and Juan Zou. All rights reserved. Solid-Phase Organic Synthesis and Catalysis: Some Recent Strategies Using Alumina, Silica, and Polyionic Resins Tue, 17 Sep 2013 10:41:13 +0000 http://www.hindawi.com/journals/jcat/2013/614829/ Solid-phase organic synthesis (SPOS) and catalysis have gained impetus after the seminal discovery of Merrifield’s solid-phase peptide synthesis and also because of wide applicability in combinatorial and high throughput chemistry. A large number of organic, inorganic, or organic-inorganic hybrid materials have been employed as polymeric solid supports to promote or catalyze various organic reactions. This review article provides a concise account on our approaches involving the use of (i) alumina or silica, either having doped with metal salts or directly, and (ii) polyionic resins to either promote various organic reactions or to immobilize reagents/metal catalysts for subsequent use in hydrogenation and cross-coupling reactions. The reaction parameters, scopes, and limitations, particularly in the context of green chemistry, have been highlighted with pertinent approaches by other groups. Basudeb Basu and Susmita Paul Copyright © 2013 Basudeb Basu and Susmita Paul. All rights reserved. CO Hydrogenation over Transition Metals (Fe, Co, or Ni) Modified K/Mo2C Catalysts Tue, 03 Sep 2013 12:51:54 +0000 http://www.hindawi.com/journals/jcat/2013/195920/ Transition metals (Fe, Co, or Ni) modified K/Mo2C catalysts were prepared and investigated as catalysts for CO hydrogenation. The addition of Fe, Co, or Ni to K/Mo2C catalyst led to a sharp increase in both the activity and selectivity of , but the promotion effects were quite different and followed the sequence: Ni > Co > Fe for the activity and Fe > Co > Ni for the alcohol selectivity. For the products distributions, it also displayed some differences; Co promoter showed much higher hydrocarbon selectivity than Fe or Ni promoter, but Fe or Co promoter gave lower methane selectivity than Ni promoter, and Fe promoter showed the highest selectivity. Minglin Xiang and Juan Zou Copyright © 2013 Minglin Xiang and Juan Zou. All rights reserved. Schiff Bases: A Versatile Pharmacophore Tue, 27 Aug 2013 13:32:56 +0000 http://www.hindawi.com/journals/jcat/2013/893512/ Schiff bases are condensation products of primary amines with carbonyl compounds gaining importance day by day in present scenario. Schiff bases are the compounds carrying imine or azomethine (–C=N–) functional group and are found to be a versatile pharmacophore for design and development of various bioactive lead compounds. Schiff bases exhibit useful biological activities such anti-inflammatory, analgesic, antimicrobial, anticonvulsant, antitubercular, anticancer, antioxidant, anthelmintic, antiglycation, and antidepressant activities. Schiff bases are also used as catalysts, pigments and dyes, intermediates in organic synthesis, polymer stabilizers, and corrosion inhibitors. The present review summarizes information on the diverse biological activities and also highlights the recently synthesized numerous Schiff bases as potential bioactive core. Anu Kajal, Suman Bala, Sunil Kamboj, Neha Sharma, and Vipin Saini Copyright © 2013 Anu Kajal et al. All rights reserved. Surface Modification of Fly Ash for Active Catalysis Mon, 01 Jul 2013 13:39:04 +0000 http://www.hindawi.com/journals/jcat/2013/723957/ Fly ash based effective solid base catalyst (KF/Al2O3/fly ash473, KF/Al2O3/fly ash673, and KF/Al2O3/fly ash873) was synthesized by loading KF over chemically and thermally activated fly ash. The chemical activation was done by treating fly ash with aluminum nitrate via precipitation method followed by thermal activation at 650°C to increase the alumina content in fly ash. The increased alumina content was confirmed by SEM-EDX analysis. The alumina enriched fly ash was then loaded with KF (10 wt%) and calcined at three different temperatures 473 K, 673 K and 873 K. The amount of loaded KF was monitored by XRD, FTIR spectroscopy, SEM-EDX, TEM and Flame Atomic Absorption Spectrophotometer. The catalytic activities of the catalysts were tested in the Claisen-Schmidt condensation of benzaldehyde and 4-methoxybenzaldehyde with 2′-hydroxyacetophenone to produce 2′-hydroxychalcone and 4-methoxy-2′-hydroxychalcone respectively. Higher conversion (83%) of benzaldehyde and (89%) of 4-methoxybenzaldehyde reveals that among these heterogeneous catalysts KF/Al2O3/fly ash673 is very active. Deepti Jain, Renu Hada, and Ashu Rani Copyright © 2013 Deepti Jain et al. All rights reserved. Synthesis of Novel ZnO Having Cauliflower Morphology for Photocatalytic Degradation Study Tue, 28 May 2013 13:51:06 +0000 http://www.hindawi.com/journals/jcat/2013/940345/ ZnO nanowire morphology has been widely studied due to its unique material properties and excellent performance in electronics, optics, and photonic. Recently, photocatalytic applications of ZnO nanowire are creating an increasing interest in the environmental applications. This paper presents a low-cost and ecofriendly synthesis of ZnO with cauliflower morphology and its effectiveness in photocatalysis. Dipak Nipane, S. R. Thakare, and N. T. Khati Copyright © 2013 Dipak Nipane et al. All rights reserved. Structure and Reverse Hydrogen Spillover in Mononuclear Au0 and AuI Complexes Bonded to Faujasite Zeolite: A Density Functional Study Sat, 25 May 2013 15:52:33 +0000 http://www.hindawi.com/journals/jcat/2013/467846/ We have studied the structure of mononuclear gold supported on acidic form of faujasite zeolite in two oxidation states, namely, 0 and +1, using density functional theory. The binding of the gold monomer to the zeolite support is stronger in the oxidation state +1 than in the oxidation state 0. For the oxidation state 0, the hydrogenated clusters AuH/(2H)-FAU, AuH2/H-FAU generated by stepwise reverse hydrogen spillover from bridging OH groups of zeolite are energetically preferred over the Au/(3H)-FAU structure. Reverse hydrogen spillover of all the three acidic protons from the zeolite to the Au monomer did not lead to a stable structure. The calculated reverse hydrogen spillover energy per hydrogen atom for zeolite supported AuH and AuH2 clusters are −10.2 and −5.1 kJ/mol, respectively, in the oxidation state 0, while in the oxidation state +1 it is 20.9 kJ/mol for zeolite supported Au+H cluster. Ajanta Deka Copyright © 2013 Ajanta Deka. All rights reserved. -Butane Isomerization over Silica-Supported Heteropolyacids: Study of Some Parameters Wed, 15 May 2013 17:30:23 +0000 http://www.hindawi.com/journals/jcat/2013/828962/ Isomerization of -butane was studied on silica-supported heteropolyacids. The activity depends strongly on the solvent used for the preparation and on the polyoxometalate loading. This behavior was explained by different proportions of isolated and bulk heteropolyacids. Silicotungstic acid is inherently more selective than phosphotungstic acid. In presence of platinum and hydrogen the catalysts are stable and highly selective (more than 97%) to isobutane. A study as a function of temperature shows that there is an optimal temperature for performing the reaction. Eva Grinenval, Anthony Garron, and Frédéric Lefebvre Copyright © 2013 Eva Grinenval et al. All rights reserved. Influence of the Incorporation of Transition Metals on the Basicity of Mg,Al-Mixed Oxides and on Their Catalytic Properties for Transesterification of Vegetable Oils Tue, 16 Apr 2013 19:04:24 +0000 http://www.hindawi.com/journals/jcat/2013/685063/ The transesterification of vegetable oils produces fatty acid methyl esters (biodiesel). Biodiesel is a nonpolluting alternative fuel produced from renewable resources whose chemical and physical properties closely resemble those of the petroleum diesel fuel and does not contribute to the greenhouse effect. The use of solid catalysts makes biodiesel production processes environmentally friendly. In this work, Mg,Al-mixed oxides derived from Mg,Al-hydrotalcite-like compound with an M3+/() molar ratio of 0.25, in which Mg or Al was partially replaced by Co2+, Cu2+, Cr3+, or Fe3+, were prepared, characterized, and evaluated as catalysts for the transesterification of soybean oil with methanol. The results have indicated that the incorporation of transition metal influenced both textural and base properties. All the evaluated catalysts were active for the studied reaction. The catalytic activity followed the order Cr-MO < Co-MO < Cu-MO < Fe-MO < MO and could be explained by mesoporous volume. Paula M. Veiga, Zilacleide S. B. Sousa, Carla M. S. Polato, Marcio F. Portilho, Cláudia O. Veloso, and Cristiane A. Henriques Copyright © 2013 Paula M. Veiga et al. All rights reserved. Mineralization of Azo Dye Using Combined Photo-Fenton and Photocatalytic Processes under Visible Light Thu, 04 Apr 2013 13:52:53 +0000 http://www.hindawi.com/journals/jcat/2013/104019/ Visible-light-assisted photodegradation of an azo dye, Reactive Red 180 (RR180), in the presence of nitrogen-doped TiO2 (N-TiO2) has been studied. The photodegradation of RR180 is evaluated through decolorization studies and total organic carbon analysis. The efficacy of hydrogen peroxide (H2O2), potassium peroxomonosulfate (oxone or PMS), and potassium peroxodisulfate (PDS) in improving the photodegradation of the dye in the N-TiO2-RR180 system is also examined. The effect of combining photo-Fenton-like reaction with N-TiO2-mediated photodegradation of RR180 under visible light has been investigated. The photoactivity of N-TiO2-RR180-Fe3+/Cu2+-oxidant systems is compared with the individual techniques of photocatalysis and photo-Fenton-like reactions. The coupled system possesses superior photomineralization ability towards the abatement of RR180. Selma K. Kuriechen, Sepperumal Murugesan, and Samuel Paul Raj Copyright © 2013 Selma K. Kuriechen et al. All rights reserved. Catalytic Synthesis of Pyrazolo[3,4-d]pyrimidin-6-ol and Pyrazolo[3,4-d]pyrimidine-6-thiol Derivatives Using Nanoparticles of NaX Zeolite as Green Catalyst Thu, 04 Apr 2013 11:48:33 +0000 http://www.hindawi.com/journals/jcat/2013/657409/ An efficient and environmental benign method is reported for the synthesis of some pyrazolopyrimidine derivatives using 3-methyl-1-phenyl-5-pyrazolone with carbonyl compounds in the presence of nanozeolite Nax catalysts, solvent-free and at reflux conditions. It is noteworthy to mention that this method of the synthesis requires less time, less temperature, and better yield. Ali Gharib, Manouchehr Jahangir, Mina Roshani, Sara Moghadasi, and Reza Safee Copyright © 2013 Ali Gharib et al. All rights reserved. Synthesis of Catalysts and Its Application for Low-Temperature CO Oxidation Thu, 21 Mar 2013 14:40:36 +0000 http://www.hindawi.com/journals/jcat/2013/586364/ A series of Au/-TiO2 with various Co/Ti ratios prepared. /TiO2 was prepared by incipient wetness impregnation with aqueous solution of cobalt nitrate. Au catalysts were prepared by deposition-precipitation (DP) method at pH 7 and 338 K. The catalysts were characterized by inductively coupled plasma-mass spectrometry, temperature programming reduction, X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The reaction was carried out in a fixed bed reactor with a feed containing 1% CO in air at weight hourly space velocities of 120,000 mL/h g and 180,000 mL/h g. High gold dispersion and narrow particle size distribution were obtained by DP method. The addition of into Au/TiO2 enhanced the activity of CO oxidation significantly. Au/5%  -TiO2 had the highest catalyst among all the catalysts. was mainly in the form of nanosize Co3O4 which could stabilize the Au nanoparticles. donated partial electrons to Au. The interactions among Au, , and TiO2 account for the high catalytic activity for CO oxidation. Der-Shing Lee and Yu-Wen Chen Copyright © 2013 Der-Shing Lee and Yu-Wen Chen. All rights reserved. Novel Ni-Co-Mo-K Catalysts Supported on Multiwalled Carbon Nanotubes for Higher Alcohols Synthesis Wed, 20 Mar 2013 13:42:52 +0000 http://www.hindawi.com/journals/jcat/2013/942145/ Alkali-promoted Ni-Co-Mo catalysts supported on multiwalled carbon nanotubes (MWCNTs) were prepared using 9 wt% K, 4.5 wt% Co, and 15 wt% Mo, whereas Ni content was varied from 0 to 6 wt%. The catalysts were extensively characterized and studied for higher alcohols synthesis from synthesis gas. Alkali-promoted trimetallic catalyst with 3 wt% Ni showed the highest total alcohols yield of 0.284 gm/(gm of cat./h), ethanol selectivity of 20%, and higher alcohols selectivity of 32% at 330°C and 9.0 MPa using gas hourly space velocity (GHSV) of 3.8 m3 (STP)/kg of catalyst/h and H2 to CO molar ratio of 1.25. Venkateswara Rao Surisetty, Janusz Kozinski, and Ajay Kumar Dalai Copyright © 2013 Venkateswara Rao Surisetty et al. All rights reserved.