Synthesis of tunable Pt-Ni nanocatalyst through heterogeneous doping method

Abstract

Heterogeneous catalyst with metal nanoparticles (NPs) dispersed on functional oxides catalyze many major industrial reactions. Uniform dispersion and chemical configuration of these NPs which determines the catalytic activity is rather difficult to control due to problems such as sintering. In this study, we apply a method combining heterogeneous doping and ex-solution. This method utilizes oxidation as an in-diffusing tool of metal source inside the support grain boundaries followed by particle ex-solution in between the grains. We synthesized Pt-Ni alloy NPs on CeO$_2$, and by manipulating reducing conditions we were able to precisely control particle size and its composition and achieve a highly dispersed and stable alloy nanocatalyst. Quantitative analysis revealed that increasing synthesis temperature increased particle size and decreased particle density. Increasing synthesis time increased the size and the Pt content in the synthesized Pt-Ni NPs. We synthesized alloy nanoparticles through heterogeneous doping method on columnar CeO$_2$ and performed multiple chemical reactions in order to ensure its catalytic feasibility and durability.