Facet Engineering of Copper for Product Specific CO2 Electroreduction

The electroreduction of carbon dioxide (CO<inf>2</inf>) using copper-based catalysts presents an effective strategy for reducing greenhouse gas emissions while generating lucrative chemical feedstocks. Copper (Cu) has emerged as one of the most efficient catalysts for CO<inf>2</inf> electroreduction (CO<inf>2</inf>ER) due to its abundant availability, high selectivity, and low cost. The most extensively researched copper-based catalysts for CO<inf>2</inf>ER always depend heavily on the valence states of copper. However, the performance of Cu catalysts can also vary significantly depending on their crystallographic facets. In recent years, considerable attention has been directed toward understanding the role of crystal facets in copper-based catalysts and their impact on the electrocatalytic performance for CO<inf>2</inf>ER. This review article aims to provide a comprehensive and state of the art overview of the literature on copper-based catalysts for the electroreduction of CO<inf>2</inf> with more emphasis on the facet-dependent thin films. The primary focus is on the most recent advancements in facet-dependent copper-based catalysts in the context of CO<inf>2</inf> electroreduction, with an emphasis on enhancing selectivity for C2 products using thin film electrocatalyst. Along with this, a brief mention of the mechanistic investigations is also included. Finally, a brief perspective in this research direction is provided in addition.