P-Doped-Activated Carbon-Supported Pd Catalysts for Synthesis and Dehydrogenation of Tetradecahydrophenazine as a LOHC Substrate

This study focuses on the synthesis and characterization of palladium catalysts supported by P-doped activated carbons (ACs) for dehydrogenation of a promising LOHC technology organic substrate: tetradecahydrophenazine (H14-Phz). AC supports for these catalysts were obtained by activation of pine nut shell by H₃PO₄ and are characterized by high BET specific surface area (up to ∼2300 m²/g) with a high mesopore proportion. Such properties of ACs ensured the high dispersion of palladium nanoparticles at a high (10 wt %) Pd content. Subsequent study of catalytic H14-Phz dehydrogenation showed that residual phosphorus in activated carbons seems to affect the catalytic properties significantly. In conclusion, the study demonstrated the fundamental feasibility of synthesizing H14-Phz from lignocellulosic biomass hydrogenolysis products using the synthesized catalysts, and they can be used for the complete synthesis of LOHC substrates from biomass processing products. The same applies directly to the key process of the LOHC technology: hydrogen extraction.