Tailored Reconstruction of Polycrystalline CuO Nanorods Promotes C―C Coupling in CO2 Electroreduction

Abstract

Designing structurally robust and functionally active catalysts is essential for advancing CO2 electroreduction toward multicarbon (C2+) products. Here, a crystallinity-engineering strategy is reported to regulate the reconstruction behavior of CuO nanorod catalysts and stabilize critical surface features that promote C & horbar;C coupling. Specifically, low-polycrystalline CuO (LP-CuO) nanorods undergo directional reconstruction into rod-like metallic Cu structures under electrochemical conditions, effectively preserving surface hydroxides and partial Cu+ oxidation states. In-situ/operando X-ray absorption spectroscopy confirms the retention of Cu(OH)(2) species in LP-CuO, while surface-enhanced infrared absorption spectroscopy reveals the generation of abundant C2+ intermediates and a blueshift in interfacial water vibrations, indicating increased free water and enhanced proton-donor activity. This interplay between stabilized surface hydroxides and interfacial water dynamics enables efficient C & horbar;C coupling and selective C2+ production, achieving a partial current density of 984 mA cm(-2). The findings provide fundamental insights into the structure-function relationship of Cu-based catalysts and establish crystallinity modulation as a generalizable design principle for high-performance and durable electrocatalysts in CO2 conversion technologies.