Spin-Enhanced C-C Coupling in CO2 Electroreduction with Oxide-Derived Copper

Electrocatalytic reduction of carbon dioxide (CO2) to multicarbon (C2+) products involves intricate multiple protons and electron transfer of C-C coupling, which is dictated by not only the intrinsic reactivity but also the spin states of electrons in the catalyst. Here, we observe spin-enhanced CO2 reduction (CO2RR) electrocatalytic activity on an oxide derived copper (OD-Cu) catalyst due to the existence of a specific Cu* site that carried the magnetic moments. Due to the correlation of magnetic and catalytic properties in OD-Cu, the current density through the OD-Cu electrode increases by nearly 10% at 350 mT. The field strength and angle dependence of such magnetic field effect (MFE), together with the time-resolved measurements proved that it originated from the alignment of magnetic moments on Cu* sites. The MFE on the electrocatalytic process enabled an enhancement (up to 15%) of the CO2RR Faradaic efficiency using the OD-Cu catalyst. Importantly, the enhancement was attributed to the spinantiparallel alignment of electrons to promote C-C coupling on asymmetric Cu*-Cu sites; consequently, the optimal bias was reduced by similar to 0.2 V under the magnetic field for C2 products with Faradaic efficiency >30% and selectivity >75%. Our work uncovers a new paradigm for spin-enhanced catalysis applicable to a broad range of chemical reactions involving spin singlet products.

Automated summary

A study has discovered spin-enhanced electrocatalytic activity for CO2 reduction on oxide-derived copper catalyst, and has explained the role of magnetic moment in catalytic reactions. The study also found that spin enhancement can promote CO2 reduction, leading to increased Faradaic efficiency and selectivity.