Highly Selective CO 2 Electroreduction to CH 4 by In Situ Generated Cu 2 O Single‐Type Sites on a Conductive MOF: Stabilizing Key Intermediates with Hydrogen Bonding

It is still a great challenge to achieve high selectivity of CH 4 in CO 2 electroreduction reactions (CO 2 RR) because of the similar reduction potentials of possible products and the sluggish kinetics for CO 2 activation. Stabilizing key reaction intermediates by single type of active sites supported on porous conductive material is crucial to achieve high selectivity for single product such as CH 4 . Here, Cu 2 O(111) quantum dots with an average size of 3.5 nm are in situ synthesized on a porous conductive copper‐based metal–organic framework (CuHHTP), exhibiting high selectivity of 73 % towards CH 4 with partial current density of 10.8 mA cm −2 at −1.4 V vs. RHE (reversible hydrogen electrode) in CO 2 RR. Operando infrared spectroscopy and DFT calculations reveal that the key intermediates (such as *CH 2 O and *OCH 3 ) involved in the pathway of CH 4 formation are stabilized by the single active Cu 2 O(111) and hydrogen bonding, thus generating CH 4 instead of CO.