Nanotechnology

Electrode

Organic chemistry

Electrocatalyst

Engineering

Catalysis

Physical chemistry

Chemistry

Materials science

Graphyne

Graphene

Tungsten

Chemical engineering

Electrochemistry

Photochemistry

Physical Chemistry Chemical Physics

Electrochemical reduction of dinitrogen molecules (N2) to value-added ammonia by using renewable electricity under mild conditions is regarded as a sustainable and promising strategy for N2 fixation. However, the lack of efficient, robust and inexpensive electrocatalysts for such electrochemical reduction has prevented its wide application. Herein, we report a novel single-atom catalyst, i.e., a single tungsten (W) atom anchored on N-doped graphyne (W@N-doped graphyne) as a highly efficient and low-cost electrocatalyst for the N2 reduction reaction. The inert N[triple bond, length as m-dash]N triple bond can be sufficiently activated when an N2 molecule is adsorbed on the W atom. A single atom of W coordinated with one N atom (doping into an sp-hybridized carbon atom) exhibits the highest catalytic performance with ultra-low onset potential of 0.29 V for N2 reduction reactions. The 'distal mechanism' is identified as the most favourable catalytic pathway. Moreover, the improved electrical conductivity of W@N-doped graphyne compared to that of pristine graphyne can ensure better electron transfer efficiency during the reduction processes. Our study provides a novel electrocatalyst with excellent catalytic performance for electrochemical reduction of N2 to NH3 under ambient conditions.

Single tungsten atom supported on N-doped graphyne as a high-performance electrocatalyst for nitrogen fixation under ambient conditions