Carbon‐Anchored Molybdenum Oxide Nanoclusters as Efficient Catalysts for the Electrosynthesis of Ammonia and Urea

Abstract

The electrochemical NO ₃ ⁻ reduction and its coupling with CO ₂ can provide novel and clean routes to synthesize NH ₃ and urea, respectively. However, their practical application is still impeded by the lack of efficient catalysts with desirable Faradaic efficiency (FE) and yield rate. Herein, we report the synthesis of molybdenum oxide nanoclusters anchored on carbon black (MoO _x /C) as electrocatalyst. It affords an outstanding FE of 98.14 % and NH ₃ yield rate of 91.63 mg h ⁻¹ mg _cat. ⁻¹ in NO ₃ ⁻ reduction. Besides, the highest FE of 27.7 % with a maximum urea yield rate of 1431.5 μg h ⁻¹ mg _cat. ⁻¹ toward urea is also achieved. The formation of electron‐rich MoO _x nanoclusters with highly unsaturated metal sites in the MoO _x /C heterostructure is beneficial for enhanced catalytic performance. Studies on the mechanism reveal that the stabilization of *NO and *CO ₂NOOH intermediates are critical for the NH ₃ and urea synthesis, respectively.