Oxidação de cicloexano pelo sistema GIF : sobre-oxidação e influencia dos ligantes

Orientador : Ulf F. SchuchardtDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de QuimicaMestrad

Estudo da oxidação de cicloexano com peroxido de hidrogenio catalisada por titanossilicalita-1 (TS-1)

Orientador: Ulf F. Schuchardt, Heloise de Oliveira PastoreTese (doutorado) - Universidade Estadual de Campinas, Instituto de QuimicaDoutorad

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

Improving the Electrocatalytic Activities and CO Tolerance of Pt NPs by Incorporating TiO2 Nanocubes onto Carbon Supports

Designing efficient anode CO-tolerant electrocatalysts is critical in low-temperature fuel cell catalysts fueled either by H-2/CO or alcohol. We demonstrate that the incorporation of TiO2 nanocubes (TiO2NCs) on Carbon Vulcan supports, followed by the synthesis of Pt NPs at their surface (Pt/TiO2NCs-C material), led to improvements in performance towards the electrooxidation of carbon monoxide, ethanol, methanol, ethylene glycol, and glycerol in acidic media relative to the commercial Pt/C and Pt/TiO2-C counterparts employing commercial TiO2. The nanocubes enabled changes in the electronic properties of Pt NPs while contributing to the bifunctional mechanism as compared to Pt/C and Pt/TiO2-C with commercial TiO2. Fuel cell experiments fed with H-2/CO steam showed that Pt/TiO2NCs-C employing nanocubes was resistant to CO-poisoning, yielding superior performance in operational conditions. The results reported herein have important implications for developing electrocatalysts with superior performances in PEMFCs.Peer reviewe

One-Step synthesis of PtFe/CeO2 catalyst for the Co-Preferential oxidation reaction at low temperatures

Active Pt-based catalysts at low temperature towards the preferential oxidation of carbon monoxide in hydrogen-rich stream reaction (CO-PROX) are of great importance for H-2-fueled fuel cells, but still remain a challenge. Herein, we propose a simple approach to synthesize a highly active Pt20Fe/CeO2 catalyst employing the borohydride reduction process. Transmission electronic microscopy revealed monodispersed 2.8 nm-Pt nanoparticles on CeO2, and the role of Fe species on the activity is discussed. The excellent CO conversion of 99.6% and CO2 selectivity of 92.3% carried out at ambient temperature meet the CO-PROX requirements for an adequate supply of hydrogen in fuel cell device. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Peer reviewe