Native frustrated Lewis pairs on core-shell In@InOH enhances CO-to-formate conversion.

Strategies to efficiently activate CO by strongly inhibiting the competitive hydrogen evolution reaction process are highly desired for practical applications of the electrochemical CO reduction technique. Here, we assembled a core-shell In@InOH architecture on carbon black by one-step reduction of NaBH as a CO-to-formate catalyst with high selectivity. The stable CO-to-formate reaction originates from the creation of steritic frustrated Lewis pairs (FLPs) on the InOH shell with In-O (O, oxygen vacancies) Lewis acid, and In-OH Lewis base. During CO reduction, the electrochemically stable FLPs are capable of first capturing and stabilizing protons to protonate FLPs to In-H Lewis acid and In-OH Lewis base due to its strong steric electrostatic field; then, CO is captured and activated by the protonated FLPs to selectively produce formate. Our results demonstrated that FLPs can be created on the surface of oxyphilic single-metal catalysts efficient in accelerating CO reduction with high selectivity.