Biomass-Derived Nickel Phosphide Nanoparticles as a Robust Catalyst for Hydrogen Production by Catalytic Decomposition of C₂H₂ or Dry Reforming of CH₄

Nickel is well recognized for its high catalytic activity in hydrogen production and hydrotreating, but it experiences severe deactivation upon coke formation. The development of a nickel-based catalyst that is resilient to deactivation while maintaining its signature high activity is therefore desirable. We demonstrate a simple but effective technique for the synthesis of nickel phosphide catalysts by impregnating nickel into carbonized natural cellulose fibers (NCFs) that naturally contain phosphorus. At a sufficient annealing temperature (1100 °C), the nickel particles react with phosphorus, forming Ni2P and Ni5P4 nanoparticles. Higher annealing temperatures (>1500 °C) promote the formation of single atom nickel, which greatly supplements the catalytic performance. Our nickel phosphide catalyst exhibits a markedly superior activity and stability in the synthesis of hydrogen by C2H2 decomposition and the dry reforming of methane (DRM) compared to the Ni/Al2O3 model catalyst. The sustained activity and stability exhibited by the developed catalyst suggest its promise for other hydrotreating reactions and the hydrogen evolution reaction.