Structure-Function Correlation and Dynamic Restructuring of Cu for Highly Efficient Electrochemical CO 2 Conversion.

The increasing global demand for sustainable energy sources and emerging environmental issues have pushed the development of energy conversion and storage technologies to the forefront of chemical research. Electrochemical carbon dioxide (CO 2 ) conversion provides an attractive approach to synthesizing fuels and chemical feedstocks using renewable energy. On the path to deploying this technology, basic and applied scientific hurdles remain. Copper, as the only metal catalyst that is capable to produce C 2+ fuels from CO 2 reduction (CO 2 R), still faces challenges in the improvement of electrosynthesis pathways for highly selective fuel production. In this regard, mechanistically understanding CO 2 R on Cu-based electrocatalysts, particularly identifying the structure-function correlation, is crucial. Here, a broad view of the variable structural parameters and their complex interplay in CO 2 R catalysis on Cu was given, with the purpose of providing deep insights and guiding the future rational design of CO 2 R electrocatalysts. First, this Review described the progress and recent advances in the development of well-defined nanostructured catalysts and the mechanistic understanding on the influences from a particular structure of a catalyst, such as facet, defects, morphology, oxidation state, composition, and interface. Next, the in-situ dynamic restructuring of Cu was presented. The importance of operando characterization methods to understand the catalyst structure-sensitivity was also discussed. Finally, some perspectives on the future outlook for electrochemical CO 2 R were offered.