Two Ships in a Bottle Design for Zn-Ag-O Catalyst Enabling Selective and Long-Lasting CO2 Electroreduction

Electrochemical CO2 reduction (CO2RR) using renewable energy sources represents a sustainable means of producing carbon-neutral fuels. Unfortunately, low energy efficiency, poor product selectivity, and rapid deactivation are among the most intractable challenges of CO2RR electrocatalysts. Here, we strategically propose a two ships in a bottle design for ternary Zn-Ag-O catalysts, where ZnO and Ag phases are twinned to constitute an individual ultrafine nanoparticle impregnated inside nanopores of an ultrahigh-surface-area carbon matrix. Bimetallic electron configurations are modulated by constructing a Zn-Ag-O interface, where the electron density reconfiguration arising from electron delocalization enhances the stabilization of the *COOH intermediate favorable for CO production, while promoting CO selectivity and suppressing HCOOH generation by altering the rate-limiting step toward a high thermodynamic barrier for forming HCOO*. Moreover, the pore-constriction mechanism restricts the bimetallic particles to nanosized dimensions with abundant Zn-Ag-O heterointerfaces and exposed active sites, meanwhile prohibiting detachment and agglomeration of nanoparticles during CO2 RR for enhanced stability. The designed catalysts realize 60.9% energy efficiency and 94.1 +/- 4.0% Faradaic efficiency toward CO, together with a remarkable stability over 6 days. Beyond providing a high-performance CO2RR electrocatalyst, this work presents a promising catalyst-design strategy for efficient energy conversion.

Automated summary

This study presents a two ships in a bottle design for ternary Zn-Ag-O catalysts, with bimetallic electron configurations modulated by constructing a Zn-Ag-O interface. This design enhances CO selectivity, suppresses HCOOH generation, and achieves high energy efficiency, high CO Faradaic efficiency, and remarkable stability.