Activating Inert Perovskite Oxides for CO 2 Electroreduction via Slight Cu 2+ Doping in B-Sites.

Perovskite oxides are proven as a striking platform for developing high-performance electrocatalysts. Nonetheless, a significant portion of them show CO 2 electroreduction (CO 2 RR) inertness. Here a simple but effective strategy is reported to activate inert perovskite oxides (e.g., SrTiO 3 ) for CO 2 RR through slight Cu 2+ doping in B-sites. For the proof-of-concept catalysts of SrTi 1-x Cu x O 3 (x = 0.025, 0.05, and 0.1), Cu 2+ doping (even in trace amount, e.g., x = 0.025) can not only create active, stable CuO 6 octahedra, increase electrochemical active surface area, and accelerate charge transfer, but also significantly regulate the electronic structure (e.g., up-shifted band center) to promote activation/adsorption of reaction intermediates. Benefiting from these merits, the stable SrTi 1-x Cu x O 3 catalysts feature great improvements (at least an order of magnitude) in CO 2 RR activity and selectivity for high-order products (i.e., CH 4 and C 2+ ), compared to the SrTiO 3 parent. This work provides a new avenue for the conversion of inert perovskite oxides into high-performance electrocatalysts toward CO 2 RR.