Molecularly Dispersed Heterogenized Metallomacrocycles: Molecular Structure Sensitivity of CO2 Electrolysis

Revealing the structure-performance relationships of the molecularly dispersed heterogenized metallo-macrocycles (MDHMs) with pi-conjugated hetero-junctions is of great, yet largely unmet, significance for realizing the rational regulation of selectivity, Faradaic efficiency, and durability in the electro-chemical CO2 reduction reaction (CO2RR). Herein, we describe new insights into the molecular-structure sensitivity of the electrochemical CO2RR over the MDHMs through peripherally functionalizing the heterogenized nickel phthalocyanines with di-verse methylimidazole groups. As studied experi-mentally and theoretically, the heterointerfacial effect and self-built microenvironment of the MDHMs are significantly modulated by accurate structural clipping at the molecular level, predominately steer-ing their electrocatalytic performance for CO2-to-CO conversion in both H-type and flow electrolytic cells. Particularly, the optimized MDHM, 2MIMC beta NiPc/CNT, displays a significantly improved electrocatalytic performance for CO2RR with near-unity Faradaic efficiency and large current density. Furthermore, the paired electrolysis systems with the MDHMs as the multifunctional electrocatalysts was developed for making full use of the anodic and cathodic reactions, which shows a new and profitable prospect for ener-gy optimization, pollutant regeneration, and green electrosynthesis in a modular form, and also provides guidance for the design and synthesis of novel effi-cient yet economical electrocatalysts.

Automated summary

Revealing the structure-performance relationships of molecularly dispersed metallo-macrocycles with hetero-junctions is important for the electrochemical CO2 reduction reaction. This study provides new insights into the molecular-structure sensitivity of CO2RR over the MDHMs and demonstrates the significant modulation of electrocatalytic performance through accurate structural clipping. The optimized MDHM shows improved electrocatalytic performance for CO2RR.