Bader Charge Balance Mechanism Realizes Industrial-Grade Current Hydrogen Production
Xi Zhou, Yu Cheng, Xinnan Xu, Lifang Zhang, Shu Tian, Xiaohui Xu, Baocong Guo, Weidong Tang, Chenglin Yan, Tao Qian
Abstract
The hydrogen production technology of water splitting under a high current density is the key to solve the efficient utilization of hydrogen energy. However, it is difficult for existing catalysts to exhibit bifunctional high-current activity in the same electrolyzer, considering that the bimetallic site can endow the catalytic material asymmetry and heterogeneity and then change the intrinsic electronic structure. Herein, we constructed a La–Fe dual-site coupled self-assembled membrane electrode (D-LaFe-SAME), and the introduction of the dual site reduced the Bader charge value of the La site from 0.87 to 0.83|e|, while the Bader charge of the Fe site increased from 0.69 to 0.70|e|, thus optimizing the Bader charge value of La–Fe active sites to a close equilibrium. Consequently, the free energy barrier of the rate-determining step is optimized, and the catalytic activity is greatly improved. Prominently, the optimal D-LaFe-SAME can achieve current densities of up to 2000 mA cm –2 at very low overpotentials (−640 mV for HER and 626 mV for OER), which is even better than the commercial precious metals Pt/C and IrO 2 . Surprisingly, when we use a large area of D-LaFe-SAME for overall water splitting, it can operate stably at currents up to 4 A. The dual-site coupled strategy based on the Bader charge balance mechanism proposed in this work is crucial for the construction of an efficient and high-current electrocatalytic system for hydrogen production in the same electrolyzer and plays a key role in achieving the goals of carbon neutrality.