Electrochemical syngas production from CO2 and water with CNT supported ZnO catalysts.

Nanocrystalline ZnO/CNT with enhanced electrochemical reduction of CO 2 to syngas [Display omitted] • Faradaic efficiency of synthesis gas of more than 75% was achieved on small ZnO particles. • The H 2 /CO ratio can be tailored by the ZnO particle size. • DFT study revealed the ZnO surface stabilizes CO 2 * and COOH* intermediates, therefore more active for CO 2 activation. • ZnO is promising for electrochemical syngas production. Electrochemical reduction of CO 2 and H 2 O can provide a promising pathway to synthesis gas generation for renewable electric energy storage and fuel production with the closed anthropogenic carbon cycle. However, the lack of affordable highly active catalysts to activate the stable CO 2 and H 2 O molecules presents a substantial challenge. Here we report ZnO supported on nanocarbon as a cost-effective and active catalyst for selective conversion of CO 2 and H 2 O to predominately synthesis gas, with higher selectivity and activity compared to polycrystalline metal catalysts such as Ag and Cu. The H 2 /CO ratio can be tailored for different industrial processes by tuning the applied potential and the particle size of ZnO. Density functional theory calculations showed that the higher activity of ZnO is related to more significantly stabilized intermediates, CO 2 *, COOH, and CO* compared to Cu and Ag. Our results highlight a promising class of low-cost, abundant oxide as active electrocatalysts for synthetic fuel production from CO 2. [ABSTRACT FROM AUTHOR]