Highly Efficient, Selective, and Stable CO 2 Electroreduction on a Hexagonal Zn Catalyst

Electrocatalytic CO 2 conversion into fuel is a prospective strategy for the sustainable energy production. However, still many parts of the catalyst such as low catalytic activity, selectivity, and stability are challenging. Herein, a hierarchical hexagonal Zn catalyst showed highly efficient and, more importantly, stable performance as an electrocatalyst for selectively producing CO. Moreover, we found that its high selectivity for CO is attributed to morphology. In electrochemical analysis, Zn (101) facet is favorable to CO formation whereas Zn (002) facet favors the H 2 evolution during CO 2 electrolysis. Indeed, DFT calculations showed that (101) facet lowers a reduction potential for CO 2 to CO by more effectively stabilizing a . COOH intermediate than (002) facet. This further suggests that tuning the crystal structure to control (101)/(002) facet ratio of Zn can be considered as a key design principle to achieve a desirable product from Zn catalyst.