The graphene-meso-macroporous SiO2 supported Pt–Ni alloy nanocatalyst for preferential oxidation of CO in H2-rich gases

In this work, nanoparticles of Pt–Ni alloy were supported on a new kind of composite which composed of graphene sheets and meso-macroporous SiO2, and the composite supported Pt–Ni catalyst was applied to the preferential oxidation of CO (CO-PROX) in H2-rich gases. The bimetallic Pt–Ni alloy catalyst was characterized by using techniques of SEM, TEM, XRD, TPR, CO chemisorptions and XPS. The catalyst showed excellent catalytic performance for CO-PROX with high activity at low temperature, high selectivity and very good stability, which was attributed to the following characters of the catalyst: Pt–Ni nanoparticles were in alloy state and highly dispersed, Pt–Ni nanoparticles were preferentially loaded on the surface of graphene sheets, and the meso-macroporosity of the composite markedly improved the mass transferring ability. This is a case study, and this kind of catalysts can be extended to other gas–solid catalytic reactions.