Hierarchically porous Cu/Zn bimetallic catalysts for highly selective CO2 electroreduction to liquid C2 products

[Display omitted] •An efficient method is reported to fabricate hierarhically porours Cu/Zn alloy catalysts.•Molar ratios of the resultant Cu/Zn catalysts are precisely tuned.•The Cu/Zn alloys are catalytically active for CO2 reduction and selective towards C2 formation.•Synnergically structural and compositional advantages promote the selective electroreduction of CO2. Hierarchically macroporous-mesoporous (HMMP) Cu/Zn alloy catalysts are reported to promote CO2 electroreduction towards liquid C2 products. HMMP Cu/Zn alloys with two types of distinct pores (∼320 nm and ∼20 nm) and adjustable alloy compositions are prepared through the interfacial self-assembly of two polymer templates and metal precursors. Due to add-in synergies of hierarchically porous structures and bimetallic elemental compositions, the resultant HMMP Cu/Zn alloy catalysts remarkably promote the deep electroreduction of CO2 to liquid C2 products while simultaneously suppressing the competitive proton reduction. Among them, HMMP Cu5Zn8 exhibits the best electrocatalytic selectivity (with a very high ethanol production of 46.6 % at −0.8 V) and excellent stability (even after electrocatalysis for 11 h) towards CO2 electroreduction. This strategy allows for the reliable synthesis of other HMMP alloy nanocatalysts for a wide range of electrocatalytic applications.