Screening and selection of oxygen reduction/evolution catalysts based on metal-organic frameworks

Abstract

Due to their sluggish nature, electrocatalysts for oxygen reduction and evolution reactions (ORR/OER) are vital innovations that enable clean energy storage and production. Metal-organic frameworks present themselves as promising candidates due to their crystalline, porous, and customizable nature. The advent of data-based materials science has led to the establishment of an expansive and detailed database that collects data of more than 20,000 MOFs that has been synthesized over decades, the QMOF database. Consequently, an effective approach to screen and select promising ORR/OER electrocatalysts from this database has been designed, and the results from the screening process were synthesized and characterized. The resulting MOFs consistently exhibited relatively competent ORR/OER electrocatalytic activity, including reaching 95.1% of the peak power density of noble metal benchmark electrocatalysts in a zinc-air battery cell. However, further improvements to the descriptor of catalytic activity are necessary to yield MOFs that can surpass noble metal benchmarks.