Boron-Doped Carbon Nanotubes Supported Ni–Co Bimetallic Catalyst for Selective Hydrodeoxygenation of Guaiacol to Cyclohexanol

The rational design of catalyst structures is pivotal for achieving high activity and selectivity in hydrodeoxygenation (HDO) reactions. However, simultaneously promoting aromatic ring hydrogenation while selectively cleaving C–O(R) bonds remains a significant challenge. In this work, a series of boron-doped carbon nanotube-supported Ni–Co alloy nanoparticles (Ni–Co/BCNTs) catalysts were developed for the selective HDO of guaiacol to cyclohexanol. Comprehensive characterizations reveal that Co incorporation induces electron-rich Ni and facilitates the formation of smaller Ni–Co alloy nanoparticles, thus enhancing catalytic activity. Boron doping further promotes the dispersion of active metal nanoparticles and increases surface acidity, thereby accelerating the demethoxylation of the intermediate 2-methoxycyclohexanol to cyclohexanol. Density functional theory (DFT) calculations confirm that the superior performance of the bimetallic system originates from the enhanced adsorption of both H2 and guaiacol, as well as reduced energy barriers for the HDO of guaiacol. Finally, 15Ni–7.5Co/BCNTs achieve a cyclohexanol yield of 93.8% and exhibit excellent stability. This study offers a novel and effective strategy for designing efficient bimetallic catalysts for biomass-derived phenolic HDO.