Ni@C nanocatalysts for the highly efficient hydrogenation of maleic anhydride to γ-butyrolactone

Core-shell Ni@C catalysts with a uniform grain size distribution were synthesised via a simple hydrothermal method followed by pyrolysis carbonisation, and their catalytic performance for the liquid-phase hydrogenation of maleic anhydride (MA) was investigated herein. When the pyrolysis temperature was 350 °C, the resulting Ni@C catalyst (Ni@C-350) possessed abundant Ni/NiO heterostructures and a carbon surface layer. Among the analysed catalysts, Ni@C-350 demonstrated the lowest apparent activation energy for the hydrogenation of C C bonds ( Ea = 34.3 KJ/mol) and C O bonds ( Ea = 65.18 KJ/mol), yielding an MA conversion of 100 % and a γ-butyrolactone (GBL) selectivity of 99.89 % under mild reaction conditions (200 °C, 3 MPa hydrogen pressure, and 0.05 g catalyst). Furthermore, the Ni@C-350 catalyst exhibited high stability, with the yield of GBL above 95 % after five consecutive usage cycles. Ni@C-350 significantly outperformed other previously reported catalysts for the liquid-phase hydrogenation of MA.