Alkali cations modulating electrostatic field of frustrated Lewis pairs for CO2 electroreduction in neutral medium

Carbon dioxide reduction reaction (CO 2 RR) on highly reactive frustrated Lewis pairs (FLPs) is a promising avenue for producing high-energy-density fuels from renewable energy. Exploring the effects of alkali metal ions on FLPs electrostatic field in neutral medium is a crucial knot for highly active FLP catalyst development. Here, leveraging the distinct electrochemical stability of In-OH and Bi-OH, we create stable Lewis pairs on the Bi 0.5 In 0.5 O y shell layer of Bi 0.5 In 0.5 O y @Bi 3 In 5 core-shell assembly with coordinatively unsaturated Bi-O Vs sites (Lewis acids) and In-OH (Lewis bases) to detect alkali metal ions effects. We find that K + is able to help electrochemically stable FLPs firstly capture and stabilize protons to protonate to Bi–H Lewis acid and In–OH 2 Lewis base due to their strong steric electrostatic field; then CO 2 is captured and activated by the protonated FLPs to produce formate with high selectivity. Whereas, Li + , Na + , and Cs + will inhibit CO 2 RR and promote the competing hydrogen evolution reaction due to Li + , Na + , and Cs + breaking steric electrostatic field of FLPs by inhibiting Bi-H formation. Our results verify that modulating electrostatic field of frustrated Lewis pairs by appropriate alkali cations is a promising catalyst design concept for highly selective CO 2 RR.