Bicarbonate-Dependence for Pd-Catalyzed CO 2 Hydrogenation to Formate over an Electronegativity-Induced Bimetallic Center

作者：Xuyu Lv, Ting Luo, Chao Lv, Changjiang Wang, Qichao Wu, Yanhong Li, Mengjie Wu, Jiu‐Ju Feng, Lichun Kong, Jing Zhou, Ai‐Jun Wang, Zhengquan Li, De‐Li Chen, Yang Fa · 发表于：Journal of the American Chemical Society · 年份：2025 · DOI：10.1021/jacs.5c04023 · 被引用次数：5 · 研究领域：CO2 Reduction Techniques and Catalysts、Catalysts for Methane Reforming、Carbon dioxide utilization in catalysis

Palladium exhibits a near-zero overpotential for CO 2 reduction to formate via an electrohydrogenation pathway, but it undergoes a rapid deterioration due to surface CO accumulation. Herein, we conduct a systematic investigation into the bicarbonate electrolyte’s proton-donating capacity in adjusting CO poisoning kinetics over an electronegativity-induced PdCu bimetallic center. The surface-H adsorption and lattice-H absorption features of Pd(alloy) in varying electrolytes are determined and quantified. Theoretical calculations incorporating electronic structure analyses reveal an electronegativity-driven charge redistribution, inducing negatively charged Pd and *H adatoms over the Pd(Cu)H with a downshifted d-band center, which greatly weakens *CO and *H adsorption/absorption onto Pd sites. Potentiodynamic X-ray diffraction, X-ray absorption spectroscopy, and anodic voltammetric scans confirm that the undesired electrochemical phase transition from α-PdH to β-PdH is significantly retarded by the incorporation of Cu. Moreover, the weakened *H–Pd interaction on the PdCu system enables the bicarbonate-rich electrolyte to enhance surface-H adsorption rather than subsurface-H absorption. Combining in situ infrared spectroscopy with differential mass spectrometry, it is experimentally identified that the concentrated bicarbonate electrolyte favors the maintenance of high *OCHO coverage, thereby delaying the formation of CO in a wider potential interval (−0.3 to −0.8 V versus a rev...