Highly Dispersed Single Clusters Supported Porphyrinic Metal–Organic Frameworks for Synergetic CO <sub>2</sub> Electroreduction to CH <sub>4</sub>
Qijie Mo, Chunying Chen, Sihong Li, Haili Song, Li Zhang
Abstract
Abstract The electrocatalytic CO 2 reduction is a promising path toward the carbon‐neutral goal but remains a huge challenge due to the high activation barrier for CO 2 and poor selectivity. Herein, the highly dispersed triruthenium single cluster (Ru 3 ‐SCs) is confined into the nanospace of pyrrole‐3‐carboxylic acid (PyrA)‐modified nickel‐porphyrin‐based metal–organic framework (Ni‐PCN‐222‐PyrA) to form the composite (Ru 3 ‐SCs@Ni‐PCN‐222‐PyrA) through the pre‐coordination confinement strategy. The prepared Ru 3 ‐SCs@Ni‐PCN‐222‐PyrA can accelerate the selective reduction of CO 2 to CH 4 via electrocatalysis. Under −1.0 V versus reversible hydrogen electrode (RHE), Ru 3 ‐SCs@Ni‐PCN‐222‐PyrA affords CO 2 electroreduction to CH 4 with a high selectivity of 71.9% Faradaic efficiency. Mechanistic studies reveal that the superior reactivity can be attributed to the ensemble effect and synergistic catalysis of Ru 3 ‐SCs, in which one Ru atom is responsible for CO 2 reduction to * CO and another Ru atom promotes the water splitting to generate * H, and then the two intermediates of * CO and * H coupled to form the key intermediate of * CHO in a thermodynamically favorable way.