Cu<sub>2+1</sub>O/Ag Heterostructure for Boosting the Electrocatalytic Nitrate Reduction to Ammonia Performance
Yang Liu, Xiao-Man Yao, Xu Liu, Zhiliang Liu, Yanqin Wang
Abstract
Electrocatalytic nitrate reduction reaction (ENO 3 RR) is an alternative, sustainable, and environmentally friendly value-added NH 3 synthesis method under ambient conditions relative to the traditional Haber–Bosch process; however, its low NH 3 yield, low Faradaic efficiency (FE), low selectivity, and low conversion rate severely restrict the development. In this work, a Cu 2+1 O/Ag-CC heterostructured electrocatalyst was successfully fabricated by constructing a heterogeneous interface between Cu 2+1 O and Ag for selective electrochemical nitrate-to-ammonia conversion. The construction of the heterogeneous interface effectively promotes the synergistic effect of the catalytically active components Cu 2+1 O and Ag, which enhances the material conductivity, accelerates the interfacial electron transfer, and exposes more active sites, thus improving the performance of ENO 3 RR. Such Cu 2+1 O/Ag-CC manifests a high NH 3 yield of 2.2 mg h –1 cm –2 and a notable ammonia FE of 85.03% at the optimal applied potential of −0.74 V vs RHE in a relatively low concentration of 0.01 M NO 3 – -containing 0.1 M KOH. Moreover, it shows excellent electrochemical stability during the cycle tests. Our study not only provides an efficient catalyst for ammonia electro-synthesis from ENO 3 RR but also an effective strategy for the construction of ENO 3 RR electrocatalysts for electrocatalytic applications.