Copper‐Phthalocyanine‐based Covalent Organic Polymers for Electrocatalytic Ambient Ammonia Synthesis

Abstract

AbstractAccurate structure‐designed single‐metal‐atom doped covalent organic polymers (COPs) are expected to be one of the most promising nitrogen reduction reaction (NRR) electrocatalysts due to their adjustable metal center coordination environment.[1–3] However, pyrolysis of the material is often required to overcome the intrinsically low conductivity of COPs materials, resulting in undesirable structural changes.[4,5] Moreover, the ligand portion connected to the monomer can modulate the electronic state of the catalytic center of the monomer to achieve enhanced kinetics parts of the reaction.[6–8] To overcome this shortcoming, this study reports hybrid electrocatalysts formed by self‐assembling pristine covalent organic polymers (COPs) with oxidized carbon nanotubes (O‐CNT). The electrical conductivity of the hybridized COP/O‐CNT materials can be increased by the O‐CNT. The catalyst attains a FE of 26.8 % and a large NH3 yield rate of 12.3 ug−1 h−1 cm−2 at −0.3 V versus a reversible hydrogen electrode. DFT calculations show that the NRR process tends to choose alternation paths. Therefore, the synthesized PCuPc/O‐CNT as a stable, high‐efficiency NRR catalyst offers a valuable reference for single‐atom COPs electrocatalyst research in electrochemical nitrogen fixation.