Stable and Efficient Single-Atom Zn Catalyst for CO₂ Reduction to CH₄

Abstract

The development of highly active and durable catalysts for electrochemical reduction of CO₂ (ERC) to CH₄ in aqueous media is an efficient and environmentally friendly solution to address global problems in energy and sustainability. In this work, an electrocatalyst consisting of single Zn atoms supported on microporous N-doped carbon was designed to enable multielectron transfer for catalyzing ERC to CH₄ in 1 M KHCO₃ solution. This catalyst exhibits a high Faradaic efficiency (FE) of 85%, a partial current density of -31.8 mA cm^-2 at a potential of -1.8 V versus saturated calomel electrode, and remarkable stability, with neither an obvious current drop nor large FE fluctuation observed during 35 h of ERC, indicating a far superior performance than that of dominant Cu-based catalysts for ERC to CH₄. Theoretical calculations reveal that single Zn atoms largely block CO generation and instead facilitate the production of CH₄.