Ni-doped mesoporous carbon obtained from hydrothermal carbonization of cellulose and their catalytic hydrogenation activity study

Ni-doped spherical mesoporous carbon catalysts (Ni/C _n ) were prepared via one-pot hydrothermal carbonization of microcrystalline cellulose (MCC) with nickel acetate as the Ni source. This exhibited a high conversion rate for p-nitrophenol (PNP) hydrogenation to p-aminophenol (PAP). The obtained catalysts contained 0.87–6.84 wt% nickel content that primarily consisted of metallic nickel, with a small amount of nickel oxide. The Ni additive could be beneficial in the formation of the mesoporous structure. The results showed that as the Ni content increased, the mesoporous percentage increased. The doped Ni was monodispersed particles added into the carbon skeleton with an average particle size of 23.6 nm. They were surrounded by ordered striped carbon that exhibited a graphite-like structure. The catalytic hydrogenation reaction took place at normal temperatures and pressure exhibited high catalytic activity. The degradation rate of PNP reached 99.7% when 0.30 g of the Ni/C_0.2-900 catalysts was used for a reaction time of 40 min, with corresponding apparent rates constant of 1.68 × 10⁻³ S⁻¹, apparent activation energy of only 43.25 kJ/mol.