Elaborate tree-like Cu-Ag clusters from green electrodeposition for efficiently electrocatalyzing CO conversion into syngas.

The electrocatalytic carbon dioxide reduction (CORR) is one of the emerging technologies that can effectively transform carbon dioxide (CO) into valuable products. Electrocatalysts deriving from green synthesis methods will significantly help to establish a new green carbon cycle. Herein, a green electrodeposition method without additional reducing agents was used to synthesize Cu-Ag bimetallic catalysts, and it is shown that the combination of Cu and Ag obviously affects the morphology of the Cu-Ag catalysts, resulting in the formation of elaborate tree-like Cu-Ag clusters. An as-deposited Cu-Ag/carbon fiber (Cu-Ag/CF) catalyst exhibits high activity, selectivity and stability toward the CORR; in particular, the elaborate dendritic Cu-Ag/CF can efficiently reduce CO to syngas with high selectivity (Faradaic efficiency (FE) > 95%) at a low onset potential (-0.5 V). This work provides a rational strategy to overcome the significantly different reaction capacities during the reduction of Ag and Cu, leading to the formation of a controlled morphology of Cu-Ag, which is favourable for the design and development of highly efficient Cu or Ag catalysts green methods for electrocatalyzing the CORR.