Phase‐Dependent Electrocatalytic CO<sub>2</sub> Reduction on Pd<sub>3</sub>Bi Nanocrystals
Jia Lin, Mingzi Sun, Jie Xu, Xuan Zhao, Rui Zhou, Binbin Pan, Lu Wang, Na Han, Bolong Huang, Yanguang Li
Abstract
Abstract Alloying is a general strategy for modulating the electronic structures of catalyst materials. Compared to more common solid–solution alloys, intermetallic alloys feature well‐defined atomic arrangements and provide the unique platform for studying the structure‐performance correlations. It is, unfortunately, synthetically challenging to prepare the nanostructures of intermetallic alloys for catalysis research. In this contribution, we prepare intermetallic Pd 3 Bi nanocrystals of a uniform size via a facile solvothermal method. These nanocrystals can phase‐transform into solid solution alloy via thermal annealing while retaining a similar composition and size. In 0.1 M KHCO 3 aqueous solution, the intermetallic Pd 3 Bi can selectively reduce CO 2 to formate with high selectivity (≈100 %) and stability even at <‐0.35 V versus reversible hydrogen electrode, whereas the solid solution alloy has limited formate selectivity of <60 %. Such unique phase‐dependence is understood via theoretical simulations showing that the crystallographic ordering of Pd and Bi atoms within intermetallic alloys can suppress CO poisoning and enhance the *OCHO adsorption during electrochemical CO 2 reduction to formate.