Heteroatom Engineering in Earth-Abundant Cobalt Electrocatalyst for Energy-Saving Hydrogen Evolution Coupling with Urea Oxidation
Siyuan Tang, Zhipeng Zhang, Quanjiang Lv, Xueqing Pan, Jianling Dong, Luyu Liu, Yangyang Wan, Jian Han, Fuzhan Song
Abstract
The development of multifunctional electrocatalysts with high performance for electrocatalyzing urea oxidation-assisted water splitting is of great significance for energy-saving hydrogen production. In this work, we demonstrate a novel heteroatom engineering strategy for development of B-doped Co as a multifunctional electrocatalyst for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and urea oxidation reaction (UOR). Density functional theory (DFT) results suggest that a B dopant can efficiently adjust the electron reconstruction of the exposure of Co sites nearby and facilitate electron transfer, resulting in an optimal d-band center along with a lower Gibbs free energy barrier. Ultimately, the obtained B–Co exhibits pH-universal HER properties in various electrolytes. A highly efficient HER performance with overpotentials as low as 27, 163, and 430 mV to −10, −100, and −500 mA cm –2 in 1.0 M KOH, respectively, is observed for the B–Co electrode. More importantly, the UOR-assisted electrolyzer only requires a voltage input of 1.55 V to produce the current densities of 50 mA cm –2, resulting in a 200 mV saving-energy potential compared to water electrolysis, demonstrating its high efficiency of hydrogen production in industrial applications.