Search

The synthesis of formic acid/formate from CO 2 electrolysis is appealing for the sustainable production of fuels, which however requires highly active and selective electrocatalysts. Herein, supporting a series of phthalocyanine tin (IV) complexes on multi-walled carbon nanotubes (CNTs) generated three composite catalysts, namely SnPc@CNTs, SnPc-8 F@CNTs, and SnPc-8OCH 3 @CNTs. Electrochemical tests indicate the high activity of these three catalysts in particular SnPc-8 F@CNTs towards CO 2 -to-formate conversion with a maximal Faraday efficiency (FE) of 91.7% at − 1.2 V versus RHE and excellent stability in flow cell, comparable to thus far state-of-the-art catalysts towards CO 2 -to-formate conversion. Remarkably, when used as the cathode catalyst in membrane electrode assembly, SnPc-8 F@CNTs stably delivers a current density of 100 mA cm−2 with a FE formate of 85% at − 2.6 V for 200 h. A series of in situ spectroscopy tests and theoretical calculations demonstrate the significant effect of the electron-withdrawing F atoms on improving the catalytic activity of SnPc-8 F@CNTs. [Display omitted] • Tin phthalocyanines have been modulated by molecular engineering to enhance catalytic activity. • SnPc-8 F@CNTs stably delivers a current density of 100 mA cm−2 at a voltage of − 2.6 V for 200 h in full cell. • Electron-withdrawing F atom was revealed to improve the catalytic activity. [ABSTRACT FROM AUTHOR]