Microfluidic Tailoring of a Ru Nanodots/Carbon Heterocatalyst for Electrocatalytic Nitrogen Fixation

The electrocatalytic nitrogen reduction reaction is regarded as a promising environment-friendly method for ammonia synthesis. However, it is hardly satisfactory for meeting industrial demands, owing to its limited activity and selectivity. Herein, a continuous-flow microfluidic platform is developed to efficiently synthesize the Ru nanodots/carbon (Ru/C) hetero-catalyst. By systematically tailoring the reaction dynamics (concentration, temperature, flow ratio, and surfactant), the optimized Ru/C hetero-catalysts show an ultrafine average size (2.16 nm) and high mass loading (3.44 wt %), providing abundant active sites for strong N 2 chemisorption. Benefiting from their outstanding nature, the Ru/C hetero-catalysts possess a large ammonia yield of 7.63 μg h –1 cm –2 and a high Faradaic efficiency of 6.51% under the neutral condition (0.1 mol L –1 Na 2 SO 4 ). Our work opens an innovative pathway for controllable microfluidic tailoring of high-performance hetero-catalysts, which further promotes the development of synthetic ammonia chemical industry.