One-Step Synthesis of AuCu/TiO2 Catalysts for CO Preferential Oxidation
| Autor: | Catarine Santos Lopes Alencar, Ana Rita Noborikawa Paiva, Julio Cesar Martins da Silva, Jorge Moreira Vaz, Estevam Vitorio Spinacé |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | Materials Research, Vol 23, Iss 5 (2020) |
| Druh dokumentu: | article |
| ISSN: | 1516-1439 1980-5373 |
| DOI: | 10.1590/1980-5373-mr-2020-0181 |
| Popis: | Abstract Au/TiO2 (1wt% Au), Cu/TiO2 (1wt% Cu) and AuCu/TiO2 (1wt% AuCu) catalysts with different Au:Cu mass ratios were prepared in one-step synthesis using sodium borohydride as reducing agent. The resulting catalysts were characterized by X-ray diffraction (XRD), X-ray Dispersive Energy (EDX), Transmission Electron Microscopy (TEM) and Temperature Programmed Reduction (TPR) and tested for the preferential oxidation of carbon monoxide (CO-PROX reaction) in H2-rich gases. EDS analysis showed that the Au contents are close to the nominal values whereas for Cu these values are always lower. X-ray diffractograms showed only the peaks of TiO2 phase; no peaks of metallic Au and Cu species or oxides phases were observed. TPR and high-resolution TEM analysis showed that AuCu/TiO2 catalysts exhibited most of Au in the metallic form with particles sizes in the range of 3-5 nm and that Cu was found in the form of oxide in close contact with the Au nanoparticles and well spread over the TiO2 surface. The AuCu/TiO2 catalysts exhibited good performance in the range of 75-100 °C and presented a better catalytic activity when compared to the monometallic ones. A maximum CO conversion of 98.4% with a CO2 selectivity of 47% was obtained for Au0.50Cu0.50/TiO2 catalyst at 100oC. |
| Databáze: | Directory of Open Access Journals |
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