Tailoring the Hybrid Texture and Pore Structure of Pitch-Based Carbon to Disperse and Support Ni Nanoparticles for Efficient Phenol Hydrogenation

The design and development of porous carbons and their supported Ni-based catalysts, characterized by high activity, stability, and low cost, remain challenging in green chemical processes. In this study, petroleum pitch (PP) and biomass pitch (BP) were employed as inexpensive carbon sources, with polyacrylonitrile (PAN) serving as a texture-modifying agent, to prepare modified carbons (MCs). Porous modified carbons (PMCs) with tailored pore sizes and distributions were comparatively prepared using a nanoscale CaCO3 template and a steam activation method. The results show that pitch-based MCs with a hybrid texture can be produced by mixing 50 wt % PAN with PP or BP, followed by thermal polymerization at 400 °C and carbonization at 600 °C. Steam activation at 800 °C for 1 h enhances pore formation in hybrid MCs derived from PAN-BP compared to those derived from PAN–PP, due to differences in the molecular structures of PP and BP. In contrast, the CaCO3 template method primarily produces mesopores and macropores, whereas steam activation generates abundant micropores and mesopores in PMCs, thereby creating ideal conditions for high-quality catalyst supports. The resulting 10 wt % Ni/PMCBP catalysts demonstrate an impressive phenol conversion of 99.4% and a cyclohexanol selectivity of 94.1% after reaction at 180 °C for 2 h, outperforming reference Ni-based catalysts. Additionally, the catalytic performance of phenol hydrogenation is significantly influenced by Ni particle size, which is closely related to the texture and pore characteristics of the carbon supports. This research provides valuable insights into the rational design of PMCs as effective supports for advanced catalytic applications.