Xiaoxiao's work is accepted for publication in ACS Nano. Congratulations!

Title: Locally Varying Surface Binding Affinity on Pd-Au Nanocrystals Enhances Electrochemical Ethanol Oxidation Activity

Authors: X. Wang,# H. Yang,# M. Liu, Z. Liu, K. Liu, Z. Mu, Y. Zhang, T. Cheng,* and C. Gao*

Link to the Publisher: https://pubs.acs.org/doi/10.1021/acsnano.4c06063

Abstract: Noble metal nanocrystals face challenges in effectively catalyzing electrochemical ethanol oxidation reaction (EOR)-represented multi-step, multi-electron transfer processes, due to the linear scaling relationship among binding energies of intermediates, impeding independent optimization of individual elemental steps. Herein, we develop noble metal nanocrystals with a range of local surface binding affinities in close proximity to overcome this challenge. Experimentally, this is demonstrated by applying tensile strain to a Pd surface and decorating it with discrete Au atoms, forming a diversity of binding sites with varying affinities in close proximity for guest molecules, as evidenced by CO probing and density functional theory calculations. Such a surface enables reaction intermediates to migrate between different binding sites as needed for each elemental step, thereby reducing the energy barrier for the overall EOR when compared to reactions at a single site. On these tailored surfaces, we attain specific and mass activities of 32.7 mA cm^-2 and 47.8 A mg_Pd^-1 in EOR, surpassing commercial Pd/C by 10.9 and 43.8 times, respectively, and outperforming state-of-the-art Pd-based catalysts. These results highlight the promise of this approach in improving a variety of multi-step, multi-electron transfer reactions, which are crucial for energy conversion applications.