Role of Multi-scale Interfacial Modulation in CO2 Electroreduction to C2+ Products over Copper-Based Catalysts

Abstract

The electrochemical CO₂ reduction reaction (CO₂RR) to multi-carbon (C₂₊) products holds great promise for sustainable energy and chemical supply. Copper (Cu)-based catalysts are unique in their ability to catalyze C-C coupling, yet achieving high selectivity for C₂₊ products remains a challenge. This review systematically summarizes strategies and mechanisms for enhancing the activity and selectivity of Cu-based catalysts from the perspective of interfacial modulation. We adopt a broad definition of interface and provide a comprehensive exploration of multi-scale interface engineering, spanning from electronic structure modulation at the catalyst surface (e.g., crystal facet effects, defect engineering, bimetallic interfaces, and support effects), to the regulation of the electrical double layer (e.g., electrolyte engineering, functionalization of electrode surfaces), and further to the tailoring of the spatial microenvironment (e.g., nanoconfinement effects, hydrophilicity/hydrophobicity tuning, gas diffusion electrode design, and hierarchical porous structures). We also elucidate the impact and application of dynamic evolution of catalyst surfaces. By disclosing the underlying structure-performance relationship, this review aims to pave the way for the rational design of interface architectures, steering the field away from conventional trialand-error approaches. Finally, we outline future research directions, emphasizing the integration of theory, in-situ characterization, and experiments, and highlighting emerging frontiers such as atomic-precision fabrication, smart adaptive interfaces, and artificial intelligence-guided design.