Proton feeding from defect-rich carbon support to cobalt phthalocyanine for efficient CO2 electroreduction

ABSTRACT Electrocatalytic CO 2 reduction reaction (CO 2 RR) holds significant promise for sustainable energy conversion, with cobalt phthalocyanine (CoPc) emerging as a notable catalyst due to its high CO selectivity . However, CoPc's efficacy is hindered by its limited ability to provide sufficient proton for the protonation process, particularly at industrial current densities . Herein, we introduce defect-engineered carbon nanotubes (d-CNT) to augment proton feeding for CO 2 RR over CoPc, achieved by expediting water dissociation. Our kinetic measurements and in-situ attenuated total reflection surface-enhanced infrared absorption spectroscopy reveal d-CNT significantly enhances proton feeding, thereby facilitating CO 2 activation to *COOH in CoPc. Density functional theory calculations corroborate these findings, illustrating that d-CNT decreases the barrier to water dissociation. Consequently, the CoPc/d-CNT mixture demonstrates robust performance, achieving 500 mA cm –2 for CO 2 RR with CO selectivity exceeding 96%. Notably, CoPc/d-CNT remains stability for a duration of 20 h under a substantial current density of 150 mA cm –2 . The study broadens the scope of practical applications for molecular catalysts in CO 2 RR, marking a significant step towards sustainable energy conversion.