Innovative Single Atom Arrays for the Electrocatalytic Reaction
Single atom arrays (SAAs) represent a paradigm shift in heterogeneous catalysis, offering precise atomic-level control over active site distribution and electronic structure. Unlike conventional single atom catalysts (SACs), which suffer from random atom dispersion and limited stability, SAAs arrange isolated metal atoms in ordered one-dimensional (1D) or two-dimensional (2D) configurations, maximizing atomic utilization and enhancing catalytic efficiency for energy conversion reactions such as hydrogen evolution and CO2 reduction. This review systematically examines advanced fabrication techniques—atomic layer deposition, chemical vapor deposition, and electronic interface-guided reduction—and evaluates their impact on catalytic performance. Key challenges impeding industrial deployment include achieving uniform array architectures, mitigating atom migration under reaction conditions, and scaling synthesis while maintaining structural fidelity. Empirical data from recent studies demonstrate that SAAs can achieve exceptional selectivity and turnover frequencies, yet long-term operational stability remains a critical barrier. For instance, in-situ reconstructed Ru atom arrays on α-MnO2 exhibit enhanced acidic oxygen evolution performance, while ferroelectric nanosheet-supported 1D arrays enable efficient CO2 photoreduction. The review underscores the necessity of bridging atomic-scale design with macroscopic electrode engineering to unlock SAAs for commercial electrolyzers and fuel cells. Future research must prioritize cost-effective, scalable manufacturing and operando characterization to resolve degradation mechanisms, thereby accelerating the transition from laboratory breakthroughs to industrial clean energy technologies.