Revealing the heterogeneous catalytic kinetics of PtRu nanocatalysts at single particle level

Abstract

Comparison of the structural features and catalytic performance of bimetallic nanocatalysts will help to develop the unified understanding of the structure-reaction relationships. Single-molecule fluorescence technique was utilized to reveal the difference in catalytic kinetics among PtRu bimetallic nanocatalysts, Pt and Ru monometallic nanocatalysts at single particle level. The results show that bimetallic nanocatalysts have higher apparent rate constant and desorption rate constants relative to monometallic, which leads to their higher catalytic activity. At single particle level, the bimetallic nanocatalysts have a wider distribution of apparent rate constants, suggesting that the bimetallic nanocatalysts have higher activity heterogeneity relative to monometallic nanocatalysts. By investigating the relationship between the reaction rate and the rate of dynamic activity fluctuations, spontaneous surface restructuring and reaction-induced surface restructuring of nanoparticles were found. The surface of bimetallic nanoparticles restructuring faster, which made the bimetallic nanocatalysts more active. These findings provide new insights into the design of highly active bimetallic nanocatalysts.