@article{Peng2026, 
author = {Xiao-Hui Peng and Hai-Yan Ran and Xiao Liang and Shiyun Li and Chunjin Ren and Heng-Quan Chen and Xiao-Shun Zhou and Ya-Hao Wang and Yadong Li},
title = {Tuning interfacial water and CO–CHO coupling via Ag single atoms enhances ethylene production in CO2 reduction},
year = {2026},
journal = {Nano Research},
keywords = {single-atom catalysis, CO2 reduction, surface enhanced Raman spectroscopy, Cu nanosheet},
url = {https://www.sciopen.com/article/10.26599/NR.2026.94909077},
doi = {10.26599/NR.2026.94909077},
abstract = {Single-atom site engineering has emerged as an effective strategy for enhancing the selectivity of multicarbon products in electrochemical CO2 reduction reaction (CO2RR), yet the synergistic roles of interfacial microenvironment regulation and key intermediate evolution remain poorly understood. Herein, Ag single-atom-modified porous CuO nanosheets (Ag1-p-CuO) were constructed, and the mechanism by which Ag1 atoms regulate the evolution of interfacial intermediates and water structure to promote ethylene formation, was systematically investigated through in situ shell-isolated nanoparticle enhanced Raman spectroscopy and advanced constant-potential density functional theory calculations. The atomically dispersed 0.2 % Ag species on porous CuO enabled a maximum C2H4 Faradaic efficiency of 54% and C2+ Faradaic efficiency of 78%. In situ Raman spectra reveal that, Ag1 decoration enriches CO coverage at defective Cu step sites and reorganizes the interfacial water layer near the surface. The resulting Ag1-Cu interface enhances cation-H2O dissociation, establishing a local proton-donating environment that directs C–C bond formation toward a favorable asymmetric CO–CHO coupling pathway while lowering the hydrogenation barrier of the key ethylene precursor *CH2CHO, thereby markedly improving ethylene selectivity. This work provides new insights into single-atom catalysis mediated interfacial microenvironment and intermediate behavior for promoting multicarbon product formation in CO2RR.}
}