Shape-Induced d-Band Center Optimization of PdBiNi Nanocubes for Exclusive Oxidation of Glycerol into C3 Products

Abstract

Electrocatalytic oxidation of glycerol toward high-value C3 products on Pd-based catalysts presents a promising strategy for upgrading and converting glycerol. However, C3 intermediates often adsorb too tightly on Pd-based catalyst surfaces during glycerol oxidation, leading to C–C bond cleavage. Herein, cubic-shaped PdBi nanoparticles with tunable Ni doping levels are successfully synthesized through a one-step solvothermal method. Owing to the downshift of d-band center originating from the introduction of Bi and Ni as well as the cubic shape, the PdBiNi ternary nanocubes (NCs) exhibit excellent electrocatalytic performance for the glycerol oxidation reaction (GOR). Specifically, Pd83Bi12Ni5 NCs with the lowest d-band center exhibit a specific activity of 61.12 mA cmgeo–2 and a mass activity of 5.34 A mgPd–1. Notably, the Faradaic efficiency (FE) toward C3 products exceeds 97%. In situ Fourier transform infrared spectroscopy and density functional theory calculations show that key C3 intermediates are easily desorbed from the catalyst surface, thereby suppressing C–C bond cleavage and thus preventing overoxidation into low-value products. In addition, Pd83Bi12Ni5 NCs possess long-term durability over the course of 16 cycles (1 h/cycle) with an FE for C3 products between 92.5% and 97.6% upon scale-up deployment in a flow electrolyzer, validating its feasibility in practical operations.