Affiliation:
1. College of Chemistry and Chemical Engineering Hunan Provincial Key Laboratory of Chemical Power Sources Central South University Changsha Hunan 410083 P. R. China
2. State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical Engineering Xiamen University Xiamen Fujian 361005 P. R. China
Abstract
AbstractElectron‐donating/‐withdrawing groups (EDGs/EWGs) substitution is widely used to regulate the catalytic performance of transition‐metal phthalocyanine (MPc) toward electrochemical CO2 reduction, but the corresponding structure‐activity relationships and regulation mechanisms are still ambiguous. Herein, by investigating a series of substitution‐functionalized MPc (MPc‐X), this work reveals a double‐volcano‐like relationship between the electron‐donating/‐withdrawing abilities of the substituents and the catalytic activities of MPc‐X. The weak‐EDG/‐EWG substitution enhances whereas the strong‐EDG/‐EWG substitution mostly lowers the CO selectivity of MPc. Experimental and calculation results demonstrate that the electronic properties of the substituents influence the symmetry and energy of the highest occupied molecular orbitals of MPc‐X, which in turn determine the CO2 adsorption/activation and lead to diverse CO2 reduction pathways on the EWG or EDG substituted MPc via different CO2 adsorption modes. This work provides mechanism insights that could be guidance for the design and regulation of molecular catalysts.
Funder
National Natural Science Foundation of China
Natural Science Foundation of Hunan Province
Subject
Biomaterials,Biotechnology,General Materials Science,General Chemistry