Electrochemical conversion of N2 to NH3 under ambient conditions is a promising and environmentally friendly route compared with the CO2-emitting and energy-intensive Haber-Bosch process. Nevertheless, due to ultrahigh stability of N2, it is urgent to explore efficient catalysts to weaken and activate the N≡N bond. Here, we report the Mo-doped iron phosphide (Mo-FeP) nanosphere as a valid transition-metal-based catalyst for electrochemical N2-to-NH3 fixation under ambient conditions. This catalyst exhibits excellent catalytic performance with a NH4+ yield rate (13.1 μg h-1 mg-1) and Faradaic efficiency (7.49%) at -0.3 and -0.2 V vs reversible hydrogen electrode (RHE), respectively. However, the FeP catalyst without doped Mo species displays weak catalytic performance. We found that the better catalytic performance of Mo-FeP might be due to the doping of Mo species, which is favorable for the polarization of adsorbed N2 molecules, making the N≡N bond more viable to dissociate.
Keywords: Mo-doped iron phosphide; N2 activation; electrochemical N2 reduction; heteroatom doping; polarizing N2 molecules.