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

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.([1-3]) 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.

Automated summary

To solve the low conductivity issue of covalent organic polymers (COPs), a study reports on hybrid electrocatalysts formed by self-assembling 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 synthesized PCuPc/O-CNT catalyst shows stable and high-efficiency nitrogen reduction reaction (NRR) performance, providing a valuable reference for single-atom COPs electrocatalyst research in electrochemical nitrogen fixation.