Water coordinated on Cu(I)-based catalysts is the oxygen source in CO2 reduction to CO

Abstract

Catalytic reduction of CO2 over Cu-based catalysts can produce various carbon-based products such as the critical intermediate CO, yet significant challenges remain in shedding light on the underlying mechanisms. Here, we develop a modified triple-stage quadrupole mass spectrometer to monitor the reduction of CO2 to CO in the gas phase online. Our experimental observations reveal that the coordinated H2O on Cu(I)-based catalysts promotes CO2 adsorption and reduction to CO, and the resulting efficiencies are two orders of magnitude higher than those without H2O. Isotope-labeling studies render compelling evidence that the O atom in produced CO originates from the coordinated H2O on catalysts, rather than CO2 itself. Combining experimental observations and computational calculations with density functional theory, we propose a detailed reaction mechanism of CO2 reduction to CO over Cu(I)-based catalysts with coordinated H2O. This study offers an effective method to reveal the vital roles of H2O in promoting metal catalysts to CO2 reduction.

Oxygen vacancies confined in hierarchically porous CsPbBr3@Pb-MOF through in situ structural transformation for promoting photocatalytic CO2 reduction

“…These findings suggest that the O atom in the produced CO is not solely derived from CO 2 , but can also originate from H 2 O. This observation is consistent with the findings reported by Zhang et al 68 Based on the experimental results and the findings of Zhang et al , two possible pathways (Fig. S23 and S24†) for photocatalytic CO 2 reduction to produce CO can be presented as follows.CO 2 + 2e − + 2H + → CO + H 2 OH 2 O + CO 2 + 2e − + 2H + → CO + 2H 2 O…”

Gas Diffusion Electrode with Microporous Layers of Hydrophobicity Gradient Distribution for CO2 Electrolysis in a Zero-Gap Electrolyzer Operated with Pure Water

“…As recent experimental and theoretical work has demonstrated the necessity of water on the elementary processes involved in CO 2 RR, , we ascertain the dual-layer capacitance ( C dl ) (Figure b and Figure S3) to reflect the surface area of the electrodes accessible to the electrolyte. Consistent with the reported studies, the GDE consisting of M40 with the most hydrophobicity shows the smallest C dl among samples.…”

Efficient strategies for promoting the electrochemical reduction of CO2 to C2+ products over Cu-based catalysts

“…Interestingly, H2O in the gas phase (g-H2O), aided by small amounts of suboxide, drives CO2 adsorption through the transition from the l-CO2 state to a bent chemisorbed species (b-CO2), which promotes the initial reduction of CO2 to form intermediates with the aid of H2O. In contrast, it was argued that H2O coordinated on Cu(I)-based catalysts, rather than free H2O, promotes CO2 adsorption and reduction to *CO [131]. Isotope-labeling experiments indicated that [Cu(H2O)] + first interacted with CO2 to form [Cu(H2O)(CO2)] + , and then a reduction reaction occurred to convert CO2 to *CO.…”