High-throughput design of bimetallic core-shell catalysts for the electrochemical nitrogen reduction reaction

Abstract

The electrochemical nitrogen reduction reaction (NRR) is an attractive alternative process for producing ammonia in an eco-friendly manner. However, the development of a highly active and selective catalyst remains a formidable challenge. Herein, 870 core-shell catalysts comprising 30 transition metals are systematically screened, and their electrochemical NRR catalytic performances are estimated using density functional theory. From the 870 core-shell catalysts, four catalysts (Pd-Ru, Pt-Re, Ir-Re, and Pd-Re) are identified as promising candidates for NRRs. Three crucial factors (strain effect, ligand effect, and shell crystal structure) that determine the catalytic performance of the core-shell catalysts are systematically explored to discover the underlying mechanisms behind the enhanced catalytic activity and selectivity observed in these proposed catalysts. The strain effect surpasses the ligand effect, and the catalytic selectivity can be enhanced by applying tensile strain to the shell layers. Additionally, the ligand effect that induces electron gain and loss modulates the adsorption properties of the intermediates, further enhancing the activity of the core-shell catalysts. Moreover, the crystal structure effects of the shell element on the electrochemical NRR are discussed for the first time in this work. Based on the three effects, we suggest a multilayered catalyst composed of three elements (Pd-Re-Ru) that exhibits catalytic activity and selectivity superior to those of the Pd-Ru core-shell catalyst. In this work, we provide insights into core-shell or multilayered catalyst designs and strategies for further enhancing their catalytic performance. Design strategies for core-shell or multilayered electrochemical NRR catalysts are suggested based on high-throughput DFT calculations of transition-metal core-shell catalysts.