Efficient Hydrodeoxygenation of Lignin-Derived Phenols to C₆₊ Cycloalkanols/Cycloalkanes over Magnetic Carbon-Encapsulated Nickel Nanospheres

Abstract

To obtain value-added fuels and chemicals from lignin, it is necessary to explore an efficient catalytic system for hydrodeoxygenation (HDO). In this study, a highly efficient and magnetically separable Ni@C catalyst was synthesized for conversion of lignin-derived phenols. Detailed results showed that the pyrolysis temperature played a crucial role in the difference of the carbon-defect degree, which increased the metal dispersion and the strong electronic metal−support interactions. Meanwhile, we revealed that the differentiated pyrolysis temperature induced the appropriate presence of Ni 2+ as Lewis acid sites and Ni δ+ as heterohydrogen cleavage sites, which provided an acceleration effect for the HDO reaction. The results displayed that higher reactivity of lignin-derived phenols into C 6+ cycloalkanols was achieved over the Ni@C catalyst (100% conversion and 87.19% selectivity). Moreover, the high selectivity of C 6+ cycloalkanes was achieved after adding H-ZSM-5 as Brønsted acid sites (100% conversion and 100% selectivity). This investigated work offers an efficient strategy for conversion of lignin-derived aromatics into value-added chemicals.

Confining redox-active metal sites in acidic porous scaffolds for the catalytic transformation of lignin-derived phenols to naphthenes

“…It has been demonstrated that acidic sites play important roles in C-O bond dissociation by synergistically cooperating with redox-active metal sites, derived from their affinity to oxygencontaining groups in phenols. [18][19][20][21][22][23][24][25] However, the addition of liquid acids in catalytic systems is corrosive to the environment.…”