Electrochemical
N2 reduction reaction (NRR) provides
an alternative approach to producing ammonia (NH3) under
ambient conditions. However, the sluggish kinetic process and existence
of the competitive reaction of hydrogen evolution reaction make the
catalytic activity and selectivity of NRR catalysts still very low.
To tackle this challenge, gold-modified molybdenum carbide (Mo2C) nanoparticles (NPs) supported on nitrogen-doped carbon
nanotubes (Au/Mo2C/NCNTs) was synthesized using a strategy
that combines laser irradiation and carbothermal reaction. For such
a composite, pony-sized Mo2C nanocrystals play important
roles in cleavage of the NN bond and the occurrence of N2 adsorption, while Au NPs promote charge transfer and intermediate
protonation to enhance the selectivity of NRR. Using these advantages,
the NH3 yield rate and Faradaic efficiency of Au/Mo2C/NCNTs reached 46.89 μg mgcat.
–1 h–1 and 2.78% at −0.3 V versus reversible
hydrogen electrode, which were 2.36 and 3.20 times those of Mo2C/NCNTs, respectively. Our effort provides a unique pathway
for preparing Au/Mo2C/NCNTs composites and gives insight
into the mechanism of the NRR performance enhanced by metal NP loading
and heteroatom doping.