Interfacial Engineering Toward Local Environment Modulation for Selective CO ₂ Electroreduction

ABSTRACT Electrochemical CO 2 reduction (CO 2 RR) holds promise for sustainable fuel and chemical production but faces fundamental challenges rooted in limited CO 2 availability and high activation reaction barriers. These issues manifest as slow kinetics, low selectivity, and poor stability under industrial operational conditions. While the catalyst/electrolyte interface engineering plays a decisive role in modulating the local microenvironment, which directly influences the kinetics and thermodynamics of CO 2 RR, current understanding remains fragmented due to the complex interplay of interfacial factors. Herein, in this review, we address this gap by moving beyond conventional categorization by materials or products. We present a unified mechanism‐oriented framework that directly links interfacial design strategies for tackling the core challenges of CO 2 availability, site accessibility, and reaction affordability. We systematically decouple the interface interactions and survey interfacial engineering strategies for CO 2 reduction, including mass‐transport control, electrostatic microenvironment tuning, molecular functionalization, and device–interface engineering. By elucidating the mechanistic principles behind these strategies and their interconnections, this review provides actionable guidelines for engineering robust interfaces that break inherent trade‐offs among activity, selectivity, and stability. We aim for this perspective to not only advance understanding of microenvironment modulation but also accelerate the development of scalable, carbon‐neutral energy conversion technologies.