Cu-based heterojunction catalysts for electrocatalytic nitrate reduction to ammonia
Abstract
Copper-based catalysts have received wide attention in the field of electrocatalytic nitrate reduction for ammonia production due to their low hydrogen precipitation activity and high ammonia selectivity. However, they still face the problems of poor stability and low activity which limit their further application. In this study, we report a Cu2O/Cu heterojunction catalyst loaded on nitrogen-doped porous carbon for nitrate reduction. The nitrogen-doped porous carbon as a carrier not only enhances the stability of the catalyst, but also facilitates the exposure and dispersion of the active sites. The maximum production rate of ammonia reaches 8.8 mg mg‒1cat h‒1 with a Faradaic efficiency of 92.8% at -1.29 V (vs. RHE). High resolution transmission electron microscopy (HRTEM) and X-Ray Diffraction (XRD) results proved the existence of Cu2O/Cu heterojunctions, which serve as an active phase. This study found the effect of the ratio of Cu2O and Cu in the heterojunction on catalytic performance, which is of great significance for the construction of efficient nitrate reduction catalysts for ammonia production.
