Kraft Lignin Derived Molybdenum Carbide/Nitrogen-Doped Carbon Composite for Efficient Hydrogen Evolution Reaction

This paper reports a simple, unique, and eco-friendly fabrication method for composites of molybdenum carbide nanoparticles dispersed on nitrogen-doped carbon supports (Mo2C/NC) by annealing of MoCl5, kraft lignin, urea at 750 °C under N2 flow in one pot. Kraft lignin, a by-product from the pulping industry, acted as carbon source for formation of Mo2C and carbon support and a cheap urea provided a nitrogen source for nitrogen-doping to carbon supports. The resultant Mo2C/NC catalysts exhibited high activity with small overpotential (131 mV at 10 mA cm−2) and excellent stability over 3000 potential cycles for hydrogen evolution reaction (HER) in alkaline media. Enhanced HER activity of Mo2C/NC catalyst was attributed to highly active Mo2C nanoparticles and nitrogen-doped carbon (N-doped carbon) providing large surface area and high electrical conductivity.