Pub Date : 2012-11-01DOI: 10.2174/1876214X01205010056
Swapan Das, M. Bhunia, A. Bhaumik
D-hexagonal mesoporous iron silicate (HMFeS) has been synthesized hydrothermally in the presence of a mixture of an amphiphilic triblock copolymer, pluronic F127 and 1,2,4-trivinylcyclohexane (TVCH) as swelling agent under acidic aqueous conditions. The direct incorporation of iron(III) into 2D-hexagonal silicate framework can be monitored in a optimized molar ratio of water and hydrochloric acid. The mesophase of the materials was investigated by using small-angle powder X-ray diffractions (PXRD), transmission electron microscopy (TEM) image analysis and nitrogen adsorption/desorption studies. TEM image and PXRD revealed that the material had 2D-hexagonal mesoporous architecture. The morphology of the material was investigated by using scanning electron microscope (SEM) and framework bonding by utilizing FT IR spectroscopy. The atomic absorption spectrophotometer (AAS) was used to estimate the incorporated iron sites within the silicate framework. BET surface area (780 m 2 g -1 ) and peak pore size of HMFeS (10.07 nm) is much higher than the pure silica SBA-15 (611 m 2 g -1 and peak pore size of 9.09 nm). This mesoporous material (HMFeS) acts as a very good catalyst in the Friedel Craft benzylation and benzoylation reactions of arenes under optimized reaction condition using benzyl chloride and benzoyl chloride as the bezylating and benzoylating agents, respectively.
以两亲性三嵌段共聚物、pluronic F127和1,2,4-三乙烯基环己烷(TVCH)为溶胀剂，在酸性条件下水热合成了d -六方介孔硅酸铁(HMFeS)。在优化的水和盐酸的摩尔比下，可以监测铁(III)直接掺入二维六方硅酸盐框架。采用小角粉末x射线衍射(PXRD)、透射电子显微镜(TEM)图像分析和氮气吸附/解吸研究对材料的中间相进行了研究。TEM和PXRD分析表明，该材料具有二维六方介孔结构。利用扫描电子显微镜(SEM)和红外光谱(FT IR)对材料的形貌进行了研究。采用原子吸收分光光度计(AAS)测定了硅酸盐骨架内的铁结合位点。HMFeS的BET表面积(780 m 2 g -1)和峰值孔径(10.07 nm)远高于纯二氧化硅SBA-15 (611 m 2 g -1)和峰值孔径(9.09 nm)。该介孔材料(HMFeS)在以氯化苄和苯甲酰氯为苯甲酰化剂和苯甲酰化剂的优化反应条件下，对芳烃的Friedel Craft苯甲酰化反应和苯甲酰化反应有很好的催化作用。
{"title":"Direct Synthesis of 2D-Hexagonal Mesoporous Iron Silicate and its Catalytic Activity for Selective Friedel-Crafts Alkylation","authors":"Swapan Das, M. Bhunia, A. Bhaumik","doi":"10.2174/1876214X01205010056","DOIUrl":"https://doi.org/10.2174/1876214X01205010056","url":null,"abstract":"D-hexagonal mesoporous iron silicate (HMFeS) has been synthesized hydrothermally in the presence of a mixture of an amphiphilic triblock copolymer, pluronic F127 and 1,2,4-trivinylcyclohexane (TVCH) as swelling agent under acidic aqueous conditions. The direct incorporation of iron(III) into 2D-hexagonal silicate framework can be monitored in a optimized molar ratio of water and hydrochloric acid. The mesophase of the materials was investigated by using small-angle powder X-ray diffractions (PXRD), transmission electron microscopy (TEM) image analysis and nitrogen adsorption/desorption studies. TEM image and PXRD revealed that the material had 2D-hexagonal mesoporous architecture. The morphology of the material was investigated by using scanning electron microscope (SEM) and framework bonding by utilizing FT IR spectroscopy. The atomic absorption spectrophotometer (AAS) was used to estimate the incorporated iron sites within the silicate framework. BET surface area (780 m 2 g -1 ) and peak pore size of HMFeS (10.07 nm) is much higher than the pure silica SBA-15 (611 m 2 g -1 and peak pore size of 9.09 nm). This mesoporous material (HMFeS) acts as a very good catalyst in the Friedel Craft benzylation and benzoylation reactions of arenes under optimized reaction condition using benzyl chloride and benzoyl chloride as the bezylating and benzoylating agents, respectively.","PeriodicalId":22755,"journal":{"name":"The Open Catalysis Journal","volume":"5 1","pages":"56-65"},"PeriodicalIF":0.0,"publicationDate":"2012-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88101969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-09-07DOI: 10.2174/1876214X01205010031
R. Tiwari, B. Rana, R. Kumar, A. Sinha
Titania-zirconia mixed oxide was developed as support for Mo, CoMo and NiMo catalysts. Synthesis was carried out using evaporation induced self assembly and modified sol-gel templating route. The samples were calcined in a temperature range of 400 o C to 600 o C. SEM and porosity analyses were used to ensure that the mesostructure is stable after Mo and promoter incorporation. Wide-angle XRD was used to verify MoO3 (and MoS2) dispersion, which indicated crystallite size <40A up to 8wt% Mo loading. The IR spectral studies were used to determine the nature of Mo species (octahedral and tetrahedral). TPD study was used to determine the acidity of the supports. The physico-chemical properties were correlated with the catalytic hydrodesulfurization reaction. CoMo and NiMo catalysts were compared in order to gain an insight into the promoter effect on direct desulfurization pathways. A comparison with -Al2O3, SBA-15 and KIT-6 supported catalysts shows much superior activities of mesoporous titania-zirconia supported catalysts which is attributed to favorable metal-support interactions in case of mesoporous titania-zirconia supported catalysts.
{"title":"TiO2-ZrO2 Binary Oxides for Effective Hydrodesulfurization Catalysts","authors":"R. Tiwari, B. Rana, R. Kumar, A. Sinha","doi":"10.2174/1876214X01205010031","DOIUrl":"https://doi.org/10.2174/1876214X01205010031","url":null,"abstract":"Titania-zirconia mixed oxide was developed as support for Mo, CoMo and NiMo catalysts. Synthesis was carried out using evaporation induced self assembly and modified sol-gel templating route. The samples were calcined in a temperature range of 400 o C to 600 o C. SEM and porosity analyses were used to ensure that the mesostructure is stable after Mo and promoter incorporation. Wide-angle XRD was used to verify MoO3 (and MoS2) dispersion, which indicated crystallite size <40A up to 8wt% Mo loading. The IR spectral studies were used to determine the nature of Mo species (octahedral and tetrahedral). TPD study was used to determine the acidity of the supports. The physico-chemical properties were correlated with the catalytic hydrodesulfurization reaction. CoMo and NiMo catalysts were compared in order to gain an insight into the promoter effect on direct desulfurization pathways. A comparison with -Al2O3, SBA-15 and KIT-6 supported catalysts shows much superior activities of mesoporous titania-zirconia supported catalysts which is attributed to favorable metal-support interactions in case of mesoporous titania-zirconia supported catalysts.","PeriodicalId":22755,"journal":{"name":"The Open Catalysis Journal","volume":"265 1","pages":"39-49"},"PeriodicalIF":0.0,"publicationDate":"2012-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73012453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-07-05DOI: 10.2174/1876214X01205010021
M. Mazhar, A. Siddiqa, H. Javid, M. Siddiq
Sulfur doped titanium dioxide anatase nano-photocatalyst with different copper loadings (5, 10, 15, and 20 w/w %) was synthesized by hydrothermal method. The fabricated nanocatalysts were found to have high surface area, high aspect ratio, good surface morphology and high metals dispersion. The synthesized nanocatalysts were characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), Energy dispersive X-ray (EDX), Brunauer Emmett teller method (BET). The results revealed that photocatalyst possesses anatase phase having particle size in the range of 9 to 12nm. The band gap of the photocatalyst was determined using transformed diffuse reflectance spectroscopy according to the Kubelka-Munk theory, showed prominent band gap decrease with increase in the Cu loadings. The photocatalytic activity of S-TiO2 and copper loaded S-TiO2 nanocatalyst were determined for degradation of phenol into hydrocarbons (methane, ethene, and propene) and photo reduction of CO2 into ethanol. The activity results revealed that degradation of phenol and photoreduction of CO2 increased with increasing copper loadings, due to creation of electronically modified active sites and change in the electron accepting properties of TiO2 with Cu addition and creation of electron hole pair.
{"title":"Cu-S Coped TiO 2 NanoPhotocatalyst for the Degradation of Environmental and Industrial Pollutants","authors":"M. Mazhar, A. Siddiqa, H. Javid, M. Siddiq","doi":"10.2174/1876214X01205010021","DOIUrl":"https://doi.org/10.2174/1876214X01205010021","url":null,"abstract":"Sulfur doped titanium dioxide anatase nano-photocatalyst with different copper loadings (5, 10, 15, and 20 w/w %) was synthesized by hydrothermal method. The fabricated nanocatalysts were found to have high surface area, high aspect ratio, good surface morphology and high metals dispersion. The synthesized nanocatalysts were characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), Energy dispersive X-ray (EDX), Brunauer Emmett teller method (BET). The results revealed that photocatalyst possesses anatase phase having particle size in the range of 9 to 12nm. The band gap of the photocatalyst was determined using transformed diffuse reflectance spectroscopy according to the Kubelka-Munk theory, showed prominent band gap decrease with increase in the Cu loadings. The photocatalytic activity of S-TiO2 and copper loaded S-TiO2 nanocatalyst were determined for degradation of phenol into hydrocarbons (methane, ethene, and propene) and photo reduction of CO2 into ethanol. The activity results revealed that degradation of phenol and photoreduction of CO2 increased with increasing copper loadings, due to creation of electronically modified active sites and change in the electron accepting properties of TiO2 with Cu addition and creation of electron hole pair.","PeriodicalId":22755,"journal":{"name":"The Open Catalysis Journal","volume":"55 1","pages":"21-30"},"PeriodicalIF":0.0,"publicationDate":"2012-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90436522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-02-22DOI: 10.2174/1876214X01205010008
Christopher Riley
Transition metals (Co, Mn, Fe, and Cu) were deposited as the hydrated oxides on a series of zeolites (Y, � , ZSM-5, mordenite, and ferrierite) and examined for activity for the oxidation of cyclohexane at 70°C and ambient pressure. The materials that demonstrated catalytic activity under these extremely mild conditions were the cobalt-based catalysts. The copper and copper/iron materials demonstrated stoichiometric activity for the oxidation of cyclohexane to cyclohexanol and cyclohexanone. The cobalt-based catalysts produced the intriguing products caprolactone, 1-hexanol, and 3-methyl-1-pentanol, as well as the expected cyclohexanol and cyclohexanone. Of most interest was the production of 1-hexanol, indicative of novel activity in the oxidative ring cleavage and oxidation of cyclohexane.
过渡金属(Co, Mn, Fe和Cu)作为水合氧化物沉积在一系列沸石(Y, o, ZSM-5，丝光沸石和铁素体)上，并在70°C和环境压力下测试了环己烷的氧化活性。在这些极端温和的条件下表现出催化活性的材料是钴基催化剂。铜和铜/铁材料对环己烷氧化生成环己醇和环己酮具有化学计量活性。钴基催化剂产生了令人感兴趣的产品己内酯、1-己醇和3-甲基-1-戊醇，以及预期的环己醇和环己酮。最令人感兴趣的是1-己醇的产生，这表明在氧化环裂解和环己烷氧化中具有新的活性。
{"title":"Oxidation of Cyclohexane by Transition Metal Oxides on Zeolites","authors":"Christopher Riley","doi":"10.2174/1876214X01205010008","DOIUrl":"https://doi.org/10.2174/1876214X01205010008","url":null,"abstract":"Transition metals (Co, Mn, Fe, and Cu) were deposited as the hydrated oxides on a series of zeolites (Y, � , ZSM-5, mordenite, and ferrierite) and examined for activity for the oxidation of cyclohexane at 70°C and ambient pressure. The materials that demonstrated catalytic activity under these extremely mild conditions were the cobalt-based catalysts. The copper and copper/iron materials demonstrated stoichiometric activity for the oxidation of cyclohexane to cyclohexanol and cyclohexanone. The cobalt-based catalysts produced the intriguing products caprolactone, 1-hexanol, and 3-methyl-1-pentanol, as well as the expected cyclohexanol and cyclohexanone. Of most interest was the production of 1-hexanol, indicative of novel activity in the oxidative ring cleavage and oxidation of cyclohexane.","PeriodicalId":22755,"journal":{"name":"The Open Catalysis Journal","volume":"67 1","pages":"8-13"},"PeriodicalIF":0.0,"publicationDate":"2012-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80640485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-01-16DOI: 10.2174/1876214X01205010001
P. Tandon, Shaista Z. Khanam, S. Singh
Potential of rhodium(III) chloride in catalyzing, in aqueous sulfuric acid medium, the oxidation of vicinal diols, and the kinetics of reaction of cerium(IV) with propane-1,2-diol and butane-2,3-diol catalyzed by rhodium(III) chloride was investigated. Data show that the reactions follow first order kinetics with respect to low cerium(IV) for lower concentrations, but a further increase in the oxidant concentration retards the reaction velocity. The reaction rate shows direct proportionality with respect to low concentrations of diol, which tends to become zero order at higher concentrations of the organic substrate. The Rate is first order in catalyst. Increase in the concentrations of hydrogen and cerium(III) ions show retarding effects while increase in chloride ion concentration and in turn ionic strength of the medium has a positive effect on the rate. Stoichiometry and spectral studies confirmed the formation of one molecule each of formaldehyde and acetaldehyde and two molecules of acetaldehyde as the products of oxidation in case of propane-1,2- diol and butane-2,3-diol respectively. Thermodynamic parameters like enthalpy of activation, free energy of activation and entropy values were calculated and it was found that the formation of activated complex in the case of butane-2,3-diol was easy compared to that in the case of propane-1,2-diol.
{"title":"Oxidation of Vicinal Diols by Cerium(IV) in Aqueous Acidic Media Catalyzed by Rhodium(III)","authors":"P. Tandon, Shaista Z. Khanam, S. Singh","doi":"10.2174/1876214X01205010001","DOIUrl":"https://doi.org/10.2174/1876214X01205010001","url":null,"abstract":"Potential of rhodium(III) chloride in catalyzing, in aqueous sulfuric acid medium, the oxidation of vicinal diols, and the kinetics of reaction of cerium(IV) with propane-1,2-diol and butane-2,3-diol catalyzed by rhodium(III) chloride was investigated. Data show that the reactions follow first order kinetics with respect to low cerium(IV) for lower concentrations, but a further increase in the oxidant concentration retards the reaction velocity. The reaction rate shows direct proportionality with respect to low concentrations of diol, which tends to become zero order at higher concentrations of the organic substrate. The Rate is first order in catalyst. Increase in the concentrations of hydrogen and cerium(III) ions show retarding effects while increase in chloride ion concentration and in turn ionic strength of the medium has a positive effect on the rate. Stoichiometry and spectral studies confirmed the formation of one molecule each of formaldehyde and acetaldehyde and two molecules of acetaldehyde as the products of oxidation in case of propane-1,2- diol and butane-2,3-diol respectively. Thermodynamic parameters like enthalpy of activation, free energy of activation and entropy values were calculated and it was found that the formation of activated complex in the case of butane-2,3-diol was easy compared to that in the case of propane-1,2-diol.","PeriodicalId":22755,"journal":{"name":"The Open Catalysis Journal","volume":"2 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2012-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85611511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-04DOI: 10.2174/1876214X01104010113
P. Müller, Benjamin L. Bangasser, L. Greiner, Shukrallah Na’amnieh, P. Bäuerlein, D. Vogt, C. Müller
Continuous operation of alcohol dehydrogenase (ADH) catalysed enantioselective reduction in a biphasic sytem showed gains in productivity and stability of the overall reaction system. The total turnover numbers obtained for the cofactor NADP + are high with up to 1.5� 10 4 . Productivity for (R)-2-butanol with Lactobacillus brevis ADH was up to 26 kmol (mol enzyme) 1 . Enantioselectivity was greater than 0.99 for (R)-phenylethanol and up to 0.99 for (R)-butanol.
{"title":"Stable Continuous Operation of a Biphasic Enantioselective Enzymatic Reduction","authors":"P. Müller, Benjamin L. Bangasser, L. Greiner, Shukrallah Na’amnieh, P. Bäuerlein, D. Vogt, C. Müller","doi":"10.2174/1876214X01104010113","DOIUrl":"https://doi.org/10.2174/1876214X01104010113","url":null,"abstract":"Continuous operation of alcohol dehydrogenase (ADH) catalysed enantioselective reduction in a biphasic sytem showed gains in productivity and stability of the overall reaction system. The total turnover numbers obtained for the cofactor NADP + are high with up to 1.5� 10 4 . Productivity for (R)-2-butanol with Lactobacillus brevis ADH was up to 26 kmol (mol enzyme) 1 . Enantioselectivity was greater than 0.99 for (R)-phenylethanol and up to 0.99 for (R)-butanol.","PeriodicalId":22755,"journal":{"name":"The Open Catalysis Journal","volume":"9 1","pages":"113-116"},"PeriodicalIF":0.0,"publicationDate":"2011-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82601387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-09-12DOI: 10.2174/1876214X01104010107
E. Koneva, E. V. Suslov, D. Korchagina, A. Genaev, K. Volcho, N. Salakhutdinov
The amines obtained from � -pinene and containing a phenol or pyridine fragment can be used as ligands in the asymmetric addition of diethylzinc to aromatic aldehydes; the enantiomeric excess (ee) was up to 80%. The enantioselectivity of the reaction is not very sensitive to the nature of substituents in the aromatic ring of aldehydes.
{"title":"Catalytic Asymmetric Addition of Diethylzinc to Benzaldehyde Using α- Pinene-Derived Ligands","authors":"E. Koneva, E. V. Suslov, D. Korchagina, A. Genaev, K. Volcho, N. Salakhutdinov","doi":"10.2174/1876214X01104010107","DOIUrl":"https://doi.org/10.2174/1876214X01104010107","url":null,"abstract":"The amines obtained from � -pinene and containing a phenol or pyridine fragment can be used as ligands in the asymmetric addition of diethylzinc to aromatic aldehydes; the enantiomeric excess (ee) was up to 80%. The enantioselectivity of the reaction is not very sensitive to the nature of substituents in the aromatic ring of aldehydes.","PeriodicalId":22755,"journal":{"name":"The Open Catalysis Journal","volume":"32 1","pages":"107-112"},"PeriodicalIF":0.0,"publicationDate":"2011-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83102806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-16DOI: 10.2174/1876214X01104010088
Anindita, R. Awasthi, Madhu, R. Singh
Ternary nanocomposites of Pd, Ru and nanocarbon (NC) have been prepared by the sodium borohydride reduction method and investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry techniques for their use as electrocatalysts for the methanol oxidation reaction (MOR). The study have shown that with addition of ruthenium from 1 to 50wt %, in the Pd-0.5wt %C composite, the rate of MOR initially increases, attains maximum and declines thereafter. Among ternary composites investigated, the Pd-0.5wt % C-20wt % Ru composite exhibited the greatest electrocatalytic activity. This electrode has approximately three times higher electrocatalytic activity than the base electrode (Pd-0.5wt % C). The electrochemical active surface area (� 133 m 2 /gPd) and the percentage utilization of Pd (30%) of the Pd-0.5wt % C-20wt % Ru electrode were also more than 5 times higher than that of the base electrode.
{"title":"Preparation of Nanostructured Pd-C-Ru Composite Electrodes for Alcohol Electrooxidations. Part-I: A Study of Ethanol Oxidation by Cyclic Voltammetry and Impedance Spectroscopy","authors":"Anindita, R. Awasthi, Madhu, R. Singh","doi":"10.2174/1876214X01104010088","DOIUrl":"https://doi.org/10.2174/1876214X01104010088","url":null,"abstract":"Ternary nanocomposites of Pd, Ru and nanocarbon (NC) have been prepared by the sodium borohydride reduction method and investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry techniques for their use as electrocatalysts for the methanol oxidation reaction (MOR). The study have shown that with addition of ruthenium from 1 to 50wt %, in the Pd-0.5wt %C composite, the rate of MOR initially increases, attains maximum and declines thereafter. Among ternary composites investigated, the Pd-0.5wt % C-20wt % Ru composite exhibited the greatest electrocatalytic activity. This electrode has approximately three times higher electrocatalytic activity than the base electrode (Pd-0.5wt % C). The electrochemical active surface area (� 133 m 2 /gPd) and the percentage utilization of Pd (30%) of the Pd-0.5wt % C-20wt % Ru electrode were also more than 5 times higher than that of the base electrode.","PeriodicalId":22755,"journal":{"name":"The Open Catalysis Journal","volume":"279 1","pages":"100-106"},"PeriodicalIF":0.0,"publicationDate":"2011-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78267472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-04-14DOI: 10.2174/1876214X01104010047
K. H. Reddy, V. Shashikala, N. Anand, C. Sandeep, B. D. Raju, K. R. Rao
Ag-Cu supported on activated carbon (Ag-Cu/C) catalysts with different compositions of Ag and Cu (total loading of Ag + Cu =1 weight %) were prepared by wet impregnation technique. These catalysts were characterized by BET surface area XRD, TPR, TEM and XPS. The catalytic activity of these catalysts was tested for control of microorganism in drinking water by nutrient agar coating method. Catalyst containing 0.5g each of Ag and Cu respectively exhibited superior catalytic activity compared to those of remaining compositions. The high catalytic activity possessed by this catalyst is attributed to the presence of smaller Ag particles and interaction between Ag and Cu as evidenced by XRD, TPR, XPS and TEM results respectively.
{"title":"A Study on Control of Microorganisms in Drinking Water Using Ag-Cu/C Catalysts","authors":"K. H. Reddy, V. Shashikala, N. Anand, C. Sandeep, B. D. Raju, K. R. Rao","doi":"10.2174/1876214X01104010047","DOIUrl":"https://doi.org/10.2174/1876214X01104010047","url":null,"abstract":"Ag-Cu supported on activated carbon (Ag-Cu/C) catalysts with different compositions of Ag and Cu (total loading of Ag + Cu =1 weight %) were prepared by wet impregnation technique. These catalysts were characterized by BET surface area XRD, TPR, TEM and XPS. The catalytic activity of these catalysts was tested for control of microorganism in drinking water by nutrient agar coating method. Catalyst containing 0.5g each of Ag and Cu respectively exhibited superior catalytic activity compared to those of remaining compositions. The high catalytic activity possessed by this catalyst is attributed to the presence of smaller Ag particles and interaction between Ag and Cu as evidenced by XRD, TPR, XPS and TEM results respectively.","PeriodicalId":22755,"journal":{"name":"The Open Catalysis Journal","volume":"17 1","pages":"47-53"},"PeriodicalIF":0.0,"publicationDate":"2011-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75690119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-04-14DOI: 10.2174/1876214X01104010054
J. Młochowski, W. Peczyńska‐Czoch, Magdalena Pįętka-Ottlik, Halina Wójtowicz-Młochowska
Oxidation of different groups of organic compounds, with hydroperoxides catalyzed by non-heavy metal containing low-molecular-weight compounds and enzymes is reviewed. This article is concentrated mainly on the hydrogen peroxide and tert-butyl hydroperoxide, however other less common hydroperoxides are also mentioned. Since hydroperoxides themselves are inactive toward most of the organic substrates, in situ activation of the oxidant is necessary. For this purpose various activators have been applied in stoichiometric or catalytic amounts. The carboxylic acids, nitriles, amides and urea are representative for the first category. The organocatalysts such as � -halo carbonyl compounds, ketones, imines, iminium salts, nitroxyl radicals and polyaminoacids, selenium compounds and enzymes are presented. They are involved in oxygen, and electron transfer processes whose mechanisms are briefly discussed, and their applications in laboratory and industrial synthesis are indicated.
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