Nickel‑tungsten co-doped carbon-based catalyst for high selective production of ethylene glycol from cellulose hydrogenolysis

Abstract

Nickel‑tungsten co-doped spherical carbon-based catalysts (m%Ni-n%W-GCT) are prepared by one-pot hydrothermal‑carbonization using glucose as carbon host. Structural composition of tungsten transforms from WOx → W → WCx when increasing carbonization temperature and tungsten loading content at the presence of Ni during hydrogen reduction, attributed to the occurrence of carburizing reaction. The carbon-based catalysts exhibit developed porous structures with weak and moderately strong acidity, and the Brønsted acid and total acid contents increase with promoting tungsten loading content. Investigation of m%Ni-n%W-GCT activity on catalyzing cellulose hydrogenolysis shows that the porous structure provides abundant reaction sites and facilitates reactant transportation, where the Brønsted acid sites promote hydrolyzing cellulose, and WCx is beneficial for hydrogenolysis of glucose other than direct hydrogenation and then Retro-Aldol condensation for ethylene glycol (EG). The optimized reaction condition (2 h at 230 °C and 5 MPa with 9%Ni-13.5%W-GC850 as the catalyst) delivers a cellulose conversion of 100%, with 69.2% selectivity for EG. The study provides an effective method for preparing EG from cellulose employing biomass-based carbon as the catalyst support.