Confinement of SnCuxO2+x Nanoclusters in Zeolites for High‐Efficient Electrochemical Carbon Dioxide Reduction

Abstract Electrochemical reduction of carbon dioxide (CO 2 RR) to methane has achieved impressive Faradaic efficiencies of over 40% with copper‐based catalysts including Cu 2 O, copper‐silver alloys and others. Although copper‐based catalysts work effectively in the CO 2 RR, they suffer from a major disadvantage: low selectivity of desired products due to the difficulty of regulating the intermediate coverage on the catalyst surface. Here, this work presents new SnCu x O 2+ x nanocluster electrocatalysts encapsulated in purely siliceous MFI zeolites (coded as SnCu x O 2+ x @MFI) for a high‐efficient CO 2 RR. This allows the formation of *CO intermediates in the channels of zeolites, which further undergoes a multi‐step protonation process to generate methane, a very attractive feature for Li‐CO 2 batteries that use the CO 2 RR catalyst as the cathode. The obtained SnCu 1.5 O 3.5 @MFI catalyst possesses a desired catalytic performance with the Faradaic efficiency of CO 2 reduction to methane at 66.6 ± 3.2% in a 0.1 m KHCO 3 electrolyte. Using the SnCu 1.5 O 3.5 @MFI as a cathode within a Li‐CO 2 battery, this work achieves a full discharge specific capacity of 23 000 mAh g −1 at a cut‐off voltage of 2.0 V (vs Li + /Li) and an operational life over 100 cycles at 1000 mAh g −1 cutoff specific capacity. This novel confinement catalyst offers a viable pathway to develop efficient CO 2 RR and Li‐CO 2 batteries with attractive properties for practical applications.