Over-oxidation Of Cyclohexane By The Gif System In An Atmosphere Of Pure Oxygen

The products of the cyclohexane oxidation by the Gif system were accumulated and it was found the cyclohexane is increasingly consumed by other reactions. Cyclohexanol and cyclohexanone are oxidized with smaller turnover numbers, forming cyclohexanone and 1, 4-cyclohexanedione with 30% and 10% selectivity, respectively. No low molecular weight carboxylic acids are formed. The other over-oxidation or condensation products should have a high molecular weight and have not yet been detected. © 1991.66C475

Electro-oxidation of ethanol on PtSn/CeO(2)-C electrocatalyst

PtSn/CeO(2)-C electrocatalyst was prepared in a single step by an alcohol-reduction process using ethylene glycol as solvent and reducing agent and CeO(2) (15 wt%) and Vulcan XC72 (85 wt%) as supports. The performance for ethanol oxidation was investigated by cyclic voltammetry and in situ FTIR spectroscopy. The electrocatalytic activity of the PtSn/CeO(2)-C electrocatalyst was higher than that of the PtSn/C electrocatalyst. FTIR studies for ethanol oxidation on PtSn/C electrocatalyst showed that acetaldehyde and acetic acid were the principal products formed, while on PtSn/CeO(2)-C electrocatalyst the principal products formed were CO(2) and acetic acid.FINEP-ProH<INF>2</INF>Financiadora de Estudos e Projetos (FINEP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPqFAPESPFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Study of ethanol electro-oxidation in acid environment on Pt(3)Sn/C anode catalysts prepared by a modified polymeric precursor method under controlled synthesis conditions

A carbon-supported binary Pt(3)Sn catalyst has been prepared using a modified polymeric precursor method under controlled synthesis conditions This material was characterized using X-ray diffraction (XRD). and the results indicate that 23% (of a possible 25%) of Sn is alloyed with Pt, forming a dominant Pt(3)Sn phase. Transmission election microscopy (TEM) shows good dispersion of the electrocatalyst and small particle sizes (3 6 nm +/- 1 nm) The polarization curves for a direct ethanol fuel cell using Pt(3)Sn/C as the anode demonstrated Improved performance compared to that of a PtSn/C E-TEK. especially in the intrinsic resistance-controlled and mass transfer regions. This behavior is probably associated with the Pt(3)Sn phase. The maximum power density for the Pt(3)Sn/C electrocatalyst (58 mW cm(-2)) is nearly twice that of a PtSn/C E-TEK electrocatalyst (33 mW cm(-2)) This behavior is attributed to the presence of a mixed Pt(9)Sn and Pt(3)Sn alloy phase in the commercial catalysts (C) 2009 Elsevier B V All rights reservedConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq[474742/2008-8]Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)CAPESFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP[05/59992-6]FAPESP[08/58789-0]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP[08/58788-4]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)UFABCUFAB