MBenes-supported single-atom catalysts for oxygen reduction and oxygen evolution reactions by first-principles study and machine learning

Abstract

Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are key catalytic processes in various renewable energy conversion and energy storage technologies. Herein, we systematically investigated the ORR and OER catalytic activity of the single-atom catalysts (SACs) composed of 4d/5d period transition metal (TM) atoms embedded on MBene substrates (TM-M 2 B 2 O 2 , M = Ti, Mo, and W). We found that TM dominates the catalytic activity compared to the MBene substrates. The SACs embedded with Rh, Pd, Au, and Ir exhibit excellent ORR or OER catalytic activity. Specifically, Rh-Mo 2 B 2 O 2 and Rh-W 2 B 2 O 2 are promising bifunctional catalysts with ultra-low ORR/OER overpotentials of 0.39/0.21 V and 0.19/0.32 V, respectively, lower than that of Pt/RuO 2 (0.45/0.42 V). Importantly, through machine learning, the models containing 10 element features of SACs were developed to quickly and accurately identify the superior ORR and OER electrocatalysts. Our findings provide several promising SACs for ORR and OER, and offer effective models for catalyst design.