摘要
Technological application of the electrochemical reduction of CO_(2)relies on efficient electrocatalysts.We demonstrate that the introduction of amino groups alongside the porphyrin cobalt centers in a metal-organic framework(MOF)can dramatically accelerate the electrochemical CO_(2)reduction performance.A classic cobalt porphyrin-based MOF showing moderate CO_(2)-to-CO electroreduction performance(turnover frequency[TOF]=0.20 s^(−1),Faradic efficiency[FE]=47.4%)is modified.By molecular design of the porphyrin-based ligand,amino groups are introduced alongside the cobalt center,giving remarkably enhanced CO_(2)-to-CO electroreduction performance as high as FE 99.4%,current density 7.2 mA cm^(−2),and TOF 21.17 s^(−1),in a nearneutral aqueous solution at a low overpotential of 525 mV.Density functional theory calculations showed that the prepositioned amino groups,although located not sufficiently close to the active center,serve as hydrogen-bonding donors to stabilize the intermediate Co-CO_(2)adduct and impede the formation of Co-H_(2)O adduct,which not only promotes the CO_(2)reduction reaction but also restrains the hydrogen evolution reaction.
基金
This research was supported by the National Key Research and Development Program of China(grant no.2021YFA1500401)
the National Natural Science Foundation of China(grant nos.21890380,21821003,22071272,21975290,and 21731007)
the Guangdong Pearl River Talents Program(grant no.2017BT01C161)
the Guangdong Natural Science Funds for Distinguished Young Scholar(grant no.2018B030306009).