Dynamic reconstruction of PdCu interfaces enables high-performance dimethylamine borane fuel cells

DFT identifies Pd Cu as a promising system for OH − -assisted DMAB electrooxidation. • Pd-Cu 2 (OH) 3 Cl/C is in situ reduced to a Pd Cu heterostructure during operation. • The reconstructed interface enriches local OH − to rapidly remove adsorbed hydrogen. • Direct DMAB fuel cell achieves 1.39 W cm −2 peak power density and > 100 h stability. Direct dimethylamine borane (DMAB) fuel cells are attractive energy sources due to their high energy density and favorable physicochemical properties. Although Pd-based catalysts can efficiently cleave B H bonds during DMAB oxidation reaction (DMABOR), their catalytic activity and selectivity are limited by strong hydrogen adsorption (H ad ). Density functional theory calculations reveal that introducing Cu into Pd optimizes the adsorption of OH − and borane intermediates, significantly lowering the kinetic barrier for DMAB electrooxidation. Herein, we report a Pd-Cu 2 (OH) 3 Cl heterostructure supported on XC-72 carbon (Pd-Cu 2 (OH) 3 Cl/C) that undergoes dynamic in situ reconstruction under operating conditions to form an active Pd Cu heterointerface. In situ spectroscopy reveals that the reconstructed interface enriches surface OH − species and accelerates the oxidative removal of H ad , thereby promoting borane oxidation kinetics. As a result, the assembled fuel cell delivers a peak power density of 1.39 W cm −2 , 1.8-fold higher than that of Pd/C (0.78 W cm −2 ), and maintains stable operation for over 100 h. Download: Download high-res image (166KB) Download: Download full-size image