Preparation of N-Doped Carbon Nanotubes Modified Al2O3 Supported Palladium-Nickel Bimetallic Catalyst and Its Catalytic Dehydrogenation of Dodecahydro-N-Ethylcarbazole

Abstract

Using melamine as the carbon source, the nitrogen-doped carbon nanotubes (N-CNTs) modified Al₂O₃ containing Ni (Ni/Al₂O₃@N-CNTs) was prepared via in situ growth on NiCl₂ impregnated Al₂O₃ surface through chemical vapor deposition (CVD). PdNi bimetallic catalysts (PdNi/Al₂O₃@N-CNTs) were prepared by wet impregnation-chemical reduction method using Ni/Al₂O₃@N-CNTs as the support. Al₂O₃@N-CNTs with large specific surface area and certain defect sites could improve the interaction between Pd NPs and carrier, and dispersion of Pd NPs. CNTs enhanced the conductivity of Al₂O₃ and facilitated electron transfer during the dehydrogenation reaction. The alloy structure formed by Ni and Pd reduced the electron cloud density of Pd, which increased its adsorption strength towards reactants. The synergistic effect of the above factors enhanced the efficiency of dodecahydro-N-ethylcarbazole (12H-NEC) dehydrogenation, achieving dehydrogenation efficiencies of 97.9% within 3 h and 99.1% within 6 h, respectively.