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

Abstract

Accurate 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][2][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][7][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 NH 3 yield rate of 12.3 ug À 1 h À 1 cm À 2 at À 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, highefficiency NRR catalyst offers a valuable reference for singleatom COPs electrocatalyst research in electrochemical nitrogen fixation.