Coating zero valent iron onto hollow carbon spheres as efficient electrocatalyst for N2 fixation and neutral Zn-N2 battery

Electrocatalytic nitrogen reduction is an economical, efficient and eco-friendly method for ammonia synthesis. However, the faraday efficiency is very low (less than 10%) in most reported researches. In this work, zero valent iron particles are dispersed on the surface of hollow carbon spheres (Fe-HCS) as electrocatalyst. As reductant and electron donor, zero valent iron can promote the transfer of electrons to the antibonding orbitals of N2, thereby enhancing nitrogen adsorption. Meanwhile, Fe-HCS exerts extraordinary electron transfer and faraday efficiency owing to superior electrical conductivity. Especially, Fe-2HCS-8 displays fantastic NH3 yield of 64.76 mu g h-1 mg -1 cat and faraday efficiency of 40.81%, which overwhelmingly exceeds most reported iron-based catalysts. And the excellent energy output of power density (155.52 mu W cm-2) is achieved by Zn-N2 battery. This work offers guidance for the reasonably design of zero valent metal catalysts and technology assistance toward electro-chemical nitrogen fixation and energy production.

Automated summary

This work presents the use of zero valent iron particles dispersed on the surface of hollow carbon spheres as an electrocatalyst for nitrogen reduction. The Fe-HCS catalyst exhibits high nitrogen adsorption and electron transfer efficiency, leading to a significantly improved faraday efficiency and NH3 yield compared to most reported iron-based catalysts. The study also demonstrates the achievement of high power density through a Zn-N2 battery. Overall, it provides valuable guidance for the design of zero valent metal catalysts and the development of electro-chemical nitrogen fixation and energy production.