Construction of Ln2O3@C Nanosheets for Electrocatalytic Nitrogen Reduction to Ammonia

La2O3@C catalystswith excellent NRRperformance were synthesized through the pyrolysis of La-citrate nanosheets. Lanthanidemetal possesses multiple oxide states, which endowsit with potential advantages as promising catalysts for electrochemicalammonia synthesis. A universal method was developed to prepare Ln(2)O(3)@C (Ln = La, Er, Tb, and Eu) nanosheets via calcinatingLn-citrate nanosheets under a N-2 atmosphere. Ln-citratenanosheets were obtained via a cation change method. The carbon fromthe carbonization of citrate not only supported the generated lanthanideoxide but also inhibited the aggregation of nanoparticles during thehigh-temperature calcination. La2O3@C nanosheetsdisplayed a high charger transfer ability, considerable chemical activesurface, and N-2 adsorption ability. La2O3@C nanosheets exhibited outstanding electrocatalytic nitrogenreduction reaction performance, with an NH3 productionrate of 20.59 mu g h(-1) mg(-1) and faradaic efficiency of 17.10%. Meanwhile, Eu2O3@C, Tb2O3@C, and Er2O3@C nanosheets were also synthesized with excellent electrocatalyticperformance. This study provided a method for fabricating metal oxidenanosheets for pronounced electrochemical nitrogen fixation.

Automated summary

La2O3@C catalystswith excellent nitrogen reduction reaction (NRR) performance were synthesized via pyrolysis of La-citrate nanosheets. The multiple oxide states of lanthanide metal make it a promising catalyst for electrochemical ammonia synthesis. Ln(2)O(3)@C (Ln = La, Er, Tb, and Eu) nanosheets were prepared by calcinating Ln-citrate nanosheets under a N-2 atmosphere. La2O3@C nanosheets displayed high charger transfer ability, chemical active surface, and N-2 adsorption capacity. La2O3@C nanosheets showed outstanding electrocatalytic NRR performance with an NH3 production rate of 20.59 μg/h·mg and faradaic efficiency of 17.10%. Eu2O3@C, Tb2O3@C, and Er2O3@C nanosheets with excellent electrocatalytic performance were also synthesized. This study provides a method for fabricating metal oxide nanosheets for electrochemical nitrogen fixation.