Multiscopic Microenvironment Engineering in Nitrate Electrocatalytic Reduction

Abstract The electrocatalytic reduction of nitrate (NO ₃ RR) is essential for environmental remediation and the nitrogen cycle, yet the effects of the local microenvironment at the multiple‐level on catalysis remain largely unclear. This review focuses on analyzing the impact of microenvironmental engineering on NO ₃ RR from multiscopic. Four aspects are detailed for the understanding of microenvironment regulation in NO ₃ RR, that are, electronic/molecular interactions (theory simulations), catalysts/reactants interactions (intrinsic activity modulation), solution interactions (anion/cation effect) and diffusion interactions (electrocatalytic reactor design). Additionally, the relevant in situ characterization techniques and various material systems (metals, compounds, carbon composites, and organic composites) are discussed in detail that can modulate the reaction microenvironment. Given the potential for large‐scale applications, the necessary reactor designs are also summarized at the industrial level for optimized performance. This review concludes by outlining future research directions for enhancing the NO ₃ RR microenvironment, which will be crucial for developing efficient catalysts and expanding the application of reaction microenvironments.