Selective C₃-C₄ Keto-Alcohol Production from Cellulose Hydrogenolysis over Ni-WO<i>_x</i>/C Catalysts

Abstract

Keto-alcohols, which are traditionally produced from fossil resources with multisteps, are considered as important intermediates for diversified high-value-added fine chemical synthesis due to their involved carbonyl and hydroxyl groups. Herein, direct cellulose hydrogenolysis to C3-C4 keto-alcohol products (hydroxyacetone and 1(3)-hydroxy-2-butanone) was achieved over Ni-WOx/C catalysts with an W/Ni atom ratio of 1.0–5.0. The keto-alcohol yield was proposed to strongly depend on the W/Ni ratio and the catalyst annealing temperature. The highest keto-alcohol yield of 63% was obtained at the optimal balance of basic/acidic WOx species and metallic Ni. The introduction of Ni facilitated the formation of the basic W5+ sites, which enhanced the formation of basic sites at the Ni-WOx interface. The synergistic effect between the basic W5+ and acidic oxygen vacancy (Vö) could activate the target C–O/C═O bonds, promoting the isomerization of glucose and C3-C4 aldehyde intermediates with the assistance of the interfacial Ni. The cooperative adsorption of the −OH and −C═O groups at the Ni-O-W-Vö interface stabilized the adjacent ketone and hydroxyl groups and kept the other hydroxyl groups for hydrogenolysis, obtaining the final C3-C4 keto-alcohols. This work expanded the application of cellulosic biomass, enabling the green and sustainable synthesis of the high-value C3-C4 keto-alcohol products using lignocellulosic biomass as a raw material.