Hydrogenation of N-ethylcarbazole over Ni-Ru alloy nanoparticles loaded on graphitized carbon prepared by carbothermal reduction

Highly active and stable Ni-Ru alloy nanoparticles loaded on graphitized carbon (Ni0.5Ru4.5/pg-BC) catalysts were synthesized using wet impregnation-carbothermal reduction. The morphological texture, structure and structure of Ni0.5Ru4.5/pg-BC were characterized by XRD, Raman spectroscopy, N2 physical adsorption, H2-TPR, XPS, TG and TEM. The results showed that smaller Ni-Ru alloy nanoparticles with a mean diameter of 2.8 nm could be formed on the carbon support by carbothermal reduction at 550 °C. The synergy between Ni and Ru can significantly improve the catalytic activity, and the introduction of Ni can more easily activate H2 to produce a hydrogen spillover effect. In the reaction of N-ethylcarbazole (NEC) hydrogenation to prepare 12H-NEC, the conversion of NEC was 100%, the selectivity of 12H-NEC was 99.06%, and the hydrogen storage capacity was 99.7% for 70 min at 130 °C and 6 MPa H2. In addition, the introduction of transition metals was observed to promote the partial graphitization of carbon materials and enhance the electronic transmission capability of materials. Compared to catalysts prepared by other methods, Ni0.5Ru4.5/pg-BC did not significantly decrease after 10 cycles. The excellent catalytic performance of Ni0.5Ru4.5/pg-BC was associated with the intimate contact between metal particles and carbon support.