Cross‐Scale Coupling Perspective: A New Pathway to Break the Selectivity Dilemma of Electrocatalytic Energy Conversion Reactions

Against the backdrop of global energy transition and carbon neutrality goals, electrocatalysis stands as a core technology for efficient conversion of renewable energy and green chemical synthesis, and its selectivity regulation has become a prominent research hotspot. Nevertheless, most existing studies focus merely on a single scale, such as atomic-level electronic structures or macroscopic mass transfer, while neglecting cross-scale synergistic regulation spanning from nanoactive sites to mesoscopic interfaces and further to macroscopic reactors. This renders the selectivity performance achieved under ideal laboratory conditions difficult to meet the complex dynamic requirements of industrial high-current-density and supported catalyst systems, giving rise to a distinct gap between fundamental research and industrial practical applications. This paper systematically reviews the regulation of electrocatalytic selectivity, aiming to construct a comprehensive theoretical framework for cross-scale selectivity regulation across macroscale, mesoscale, and nanoscale with full-scale coverage and in-depth elaboration. The research scope covers multiple levels, including active sites, interfacial environments, and external field responses. Future research should prioritize deepening the integration of artificial intelligence and electrocatalysis to enable intelligent catalyst design, develop self-adaptive catalyst systems to optimize dynamic reaction processes, and accelerate industrial applications in green hydrogen production, carbon dioxide conversion, and other related fields.