Boosting electrochemical CO2 reduction to CO over interfacial hydroxide-metal catalysts

Interface engineering is demonstrated to lead to significant improvement in the catalytic performance for electrochemical CO2 reduction reactions (CO2RR). In this work, we demonstrate a heterogeneous In(OH)3-Ag interface catalyst in which the appropriate In(OH)3 clusters modified on metal Ag nanoparticles surface greatly improves the CO selectivity in CO2RR, realizing a CO faradaic efficiency (FECO) of 93% at − 0.7 V vs. RHE. The performance enhancement is attributed to the preferentially CO2 adsorption and activation by the In(OH)3-Ag interface sites. In situ Raman spectroscopy reveals that the formation of In(OH)3-Ag interface sites is significantly favorable for the generation of key *CO2− intermediate at low overpotential. Further theoretical calculation confirms that the In(OH)3-Ag interface could enhance the adsorption of *COOH species on catalyst by means of tailoring the surface properties and electronic structures. This work shows that hydroxide-metal interface engineering is a promising pathway to regulate the activity for selective CO2RR properties. [Display omitted] •The hydroxide-metal interface is provided by In(OH)3-Ag to drive the CO2-to-CO with a high CO faradaic efficiency (FECO) of 93% at −0.7 V vs. RHE.•The CO selectivity is linked with the relative amount of Ag and In(OH)3.•In situ Raman and DFT calculation confirms the role of the hydroxide-metal interface in the formation and stability of key intermediates.