Abstract
Electrocatalytic CO2-to-CO conversion is crucial for advancing sustainable processes, and providing essential feedstocks for the chemical industry. Cobalt phthalocyanine (CoPc) is a well-established molecular catalyst for this conversion; however, maintaining high selectivity at industrially relevant current densities remains a significant challenge. Herein, we present a Co–N5 local structure anchored on nitrogen-doped carbon nanotubes through axial nitrogen coordination engineering to CoPc (CoPc/N-CNTs). The catalyst demonstrates near-unity CO selectivity and a high CO turnover frequency, peaking at 19.2 s−1 across a wide range of overpotentials. In flow cell tests, CoPc/N-CNTs achieve a CO Faradaic efficiency exceeding 95% at a current density of −800 mA cm−2. When integrated into a membrane electrode assembly, it maintained over 90% CO Faradaic efficiency at an industrial-scale current of −5 A for up to 20 h. Mechanistic studies revealed that Co–N5 active sites accelerate *COOH formation and inhibit deeper *CO reduction to CH3OH while reducing HER activity by lowering H2O surface coverage. These findings offer a delicate catalyst design that enables the efficient and sustained conversion of CO2 to CO.
Original language | English |
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Pages (from-to) | 252-259 |
Number of pages | 8 |
Journal | Journal of Energy Chemistry |
Volume | 107 |
DOIs | |
State | Published - Aug 2025 |
Keywords
- Axial coordination
- Cobalt phthalocyanine
- Electrochemical CO reduction
- Molecular catalysts