Unveiling the Local Structure and Electronic Properties of PdBi Surface Alloy for Selective Hydrogenation of Propyne

Building a reliable relationship between the electronic structure of alloyed metallic catalysts and catalytic performance is important but remains challenging due to the interference from many entangled factors. Herein, a PdBi surface alloy structural model, by tuning the deposition rate of Bi atoms relative to the atomic interdiffusion rate at the interface, realizes a continuous modulation of the electronic structure of Pd. Using advanced X-ray characterization techniques, we provide a precise depiction of the electronic structure of the PdBi surface alloy. As a result, the PdBi catalysts show enhanced propene selectivity compared with the pure Pd catalyst in the selective hydro-genation of propyne. The prevented formation of saturated beta- hydrides in the subsurface layers and weakened propene adsorption on the surface contribute to the high selectivity. Our work provides in-depth understanding of the electronic properties of surface alloy structure and underlies the study of the electronic structure-performance relationship in bimetallic catalysts.

Automated summary

By modulating the surface alloy structure of PdBi, the electronic structure of Pd can be continuously adjusted, leading to enhanced catalytic performance in the selective hydrogenation of propyne.