Tailoring the Antipoisoning Performance of Pd for Formic Acid Electrooxidation via an Ordered PdBi Intermetallic

Pd-based materials are promising electrocatalysts for the formic acid oxidation reaction (FAOR) but suffer from poor durability due to the poisoning of adsorbed carbon monoxide species (COads). In this work, PdBi ordered intermetallic (O-PdBi) nanoparticles were prepared in an effort to mitigate the formation of adsorbed species like COads through isolating the Pd atoms. The enhanced antipoisoning capability of O-PdBi, relative to Pd, gave rise to superior activity and stability during FAOR. Differential electrochemical mass spectrometry (DEMS) and CO stripping results indicated that COads could be removed more easily on O-PdBi compared with that on Pd. In situ attenuated total reflection-infrared spectroscopy showed that the formation of COads on O-PdBi was effectively suppressed, while both the hollow and bridged COads were detected on Pd with continuous Pd sites. In addition to the higher content of Bi atoms on the Pd-Bi surface, the ordered atomic distribution has played an important role in this effect. This work demonstrates the superiority of ordered intermetallic Pd-based nanocatalysts and provides guidance for promoting stability in FAOR by precluding the formation of COads.