Abstract: Electrocatalytic CO₂ reduction (ECR) technology enables the conversion of CO₂ into high-value chemicals, representing a key pathway for carbon resource recycling and energy transition. CH₄ is an increasingly attractive target product for CO₂ electroreduction, given its high energy density and versatile applications. This review systematically outlines the thermodynamic and kinetic characteristics of ECR toward CH₄, along with the evolution mechanisms of key intermediates. It focuses on recent design strategies for Cu-based catalysts aimed at efficient CH₄ production, including regulation of atomic coordination environments, interface and crystal phase engineering, defect construction, and doping. Furthermore, the influence of electrolyzer on gas-liquid-solid three-phase interfacial mass transport and macroscopic electrochemical performance is analyzed. Finally, the scientific issues and technical challenges facing ECR-to-CH₄ are summarized, and future research directions are discussed.

Key words: electrocatalysis, CO₂ reduction, Cu-based catalyst, CH₄, hydrogen evolution reaction