Conjugated Microporous Polymer Catalysts with Well-Defined Molecular Metal Sites and Tunable Coordination Environments for Electrocatalytic Synthesis of C-N Coupling Compounds

The electrochemical CO2 reduction reaction (CO2RR) effectively converts and fixes CO2 but currently produces a limited range of short-chain carbon-hydrogen-oxygen compounds in aqueous electrolytes. By using small molecules like nitrate as co-reactants, CO2RR can yield valuable C-N coupling products (e.g., amide, amine), expanding its applications. Although typical metal-based, single-atom, or dual-atomic-site catalysts have been reported to catalyze electrochemical C-N coupling, their inherent structural heterogeneity, arising from defect states, high-temperature pyrolysis, non-uniform support materials, and unclear active site structures/environment, limits their selectivity, energy efficiency, and utility in mechanistic studies. To progress, a well-defined system with definite coordination environments to form structurally defined active sites is crucial for advancing electrochemical C-N coupling reactions. The COMPACT-CN project aims to develop metalated conjugated microporous polymer (M-CMP) electrocatalysts with uniform molecular metal sites to explore catalytic selectivity and kinetics for C-N coupling reactions. The key objectives are: 1) to synthesize and characterize structurally engineered M-CMPs with high performance and selectivity for C-N coupling; 2) to investigate reaction mechanisms using advanced electrochemical and in situ surface-sensitive techniques; and 3) to establish the relationship between structural properties (metal site-spacing, proton relay distance, and electron push-pull effects) and C-N coupling performance. COMPACT-CN's achievements will deepen molecular-level insights into electrochemical C-N bond coupling mechanisms and structure-function relationships in catalysts, advancing CO2/NOx conversion techniques. These approaches are essential for achieving carbon neutrality by reducing CO2/NOx emissions while converting them into valuable chemicals, which are highly attractive for both academic research and industrial applications.