Theoretical Screening of CO Electroreduction over MOF-808-Supported Self-Adaptive Dual-Metal-Site Pairs.

Electrochemical CO reduction to transportation fuels and valuable platform chemicals provides a sustainable avenue for renewable energy storage and realizes an artificially closed carbon loop. However, the rational design of highly active and selective CO reduction electrocatalysts remains a challenging task. Herein, a series of metal-organic framework (MOF)-supported flexible, self-adaptive dual-metal-site pairs (DMSPs) including 21 pairwise combinations of six transition metal single sites (MOF-808-EDTA-MM, M/M = Fe, Cu, Ni, Pd, Pt, Au) for the CO reduction reaction (CORR) were theoretically screened using density functional theory calculations. Against the competitive hydrogen evolution reaction, MOF-808-EDTA-FeFe and MOF-808-EDTA-FePt were identified as the promising CORR electrocatalysts toward C and C products. The calculated limiting potential for CO electroreduction to CH and CHOH over MOF-808-EDTA-FeFe is -0.87 V. Compared with an applied potential of -0.56 eV toward CH production over MOF-808-EDTA-FeFe, MOF-808-EDTA-FePt exhibits an even better activity for CO reduction to C products at a limiting potential of -0.35 V. The present work not only identifies promising candidates for highly selective CORR electrocatalysts leading to C and C products but also provides mechanistic insights into the dynamic nature of DMSPs for stabilizing various reaction intermediates in the CORR process.