One-Step Synthesis of AuCu/TiO₂ Catalysts for CO Preferential Oxidation

Author(s)

Lopes Alencar, Catarine Santos ; Noborikawa Paiva, Ana Rita ; Martins da Silva, Julio Cesar ; Vaz, Jorge Moreira ; Spinace, Estevam Vitorio

• Document type: Journal article
• Source: MATERIALS RESEARCH-IBERO-AMERICAN JOURNAL OF MATERIALS; v. 23, n. 5, p. 6-pg., 2020-01-01.

Abstract

AuCu/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 H-2-rich gases. EDS analysis showed that the Au contents are close to the nominal values whereas for Cu these values arc 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 degrees 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 100 degrees C. (AU)

• FAPESP's process: 14/09087-4 - Studies on the use of bioethanol in proton exchange membrane and solid oxide fuel cells
• Grantee: Marcelo Linardi
• Support Opportunities: Research Projects - Thematic Grants
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• Grantee: Julio Romano Meneghini
• Support Opportunities: Research Grants - Research Centers in Engineering Program
• FAPESP's process: 17/11937-4 - A sustainable path to methane conversion by advanced electrochemical technologies
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• Support Opportunities: Research Grants - Research Centers in Engineering Program