Theoretical Screening of CO 2 Electroreduction over MOF-808-Supported Self-Adaptive Dual-Metal-Site Pairs.

Electrochemical CO 2 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 2 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-M 1 M 2 , M 1 /M 2 = Fe, Cu, Ni, Pd, Pt, Au) for the CO 2 reduction reaction (CO 2 RR) 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 CO 2 RR electrocatalysts toward C 1 and C 2 products. The calculated limiting potential for CO 2 electroreduction to C 2 H 6 and C 2 H 5 OH over MOF-808-EDTA-FeFe is -0.87 V. Compared with an applied potential of -0.56 eV toward CH 4 production over MOF-808-EDTA-FeFe, MOF-808-EDTA-FePt exhibits an even better activity for CO 2 reduction to C 1 products at a limiting potential of -0.35 V. The present work not only identifies promising candidates for highly selective CO 2 RR electrocatalysts leading to C 1 and C 2 products but also provides mechanistic insights into the dynamic nature of DMSPs for stabilizing various reaction intermediates in the CO 2 RR process.