Construction of Ln<sub>2</sub>O<sub>3</sub>@C Nanosheets for Electrocatalytic Nitrogen Reduction to Ammonia
Changchang Dong, LI Ming-hui, Xiaojun Han
Abstract
Lanthanide metal possesses multiple oxide states, which endows it with potential advantages as promising catalysts for electrochemical ammonia synthesis. A universal method was developed to prepare Ln 2 O 3 @C (Ln = La, Er, Tb, and Eu) nanosheets via calcinating Ln-citrate nanosheets under a N 2 atmosphere. Ln-citrate nanosheets were obtained via a cation change method. The carbon from the carbonization of citrate not only supported the generated lanthanide oxide but also inhibited the aggregation of nanoparticles during the high-temperature calcination. La 2 O 3 @C nanosheets displayed a high charger transfer ability, considerable chemical active surface, and N 2 adsorption ability. La 2 O 3 @C nanosheets exhibited outstanding electrocatalytic nitrogen reduction reaction performance, with an NH 3 production rate of 20.59 μg h –1 mg –1 and faradaic efficiency of 17.10%. Meanwhile, Eu 2 O 3 @C, Tb 2 O 3 @C, and Er 2 O 3 @C nanosheets were also synthesized with excellent electrocatalytic performance. This study provided a method for fabricating metal oxide nanosheets for pronounced electrochemical nitrogen fixation.