Ru-WOX-doped biochar for selective ethylene glycol production from cellulose hydrogenolysis: Unravelling the role of WOX in adjusting acid-metal balance

•The Ru-30WOx-C catalyst exhibits the best acid-metal balance (7.4).•The 3%Ru supported on 30%WOX-C exhibited the highest ethylene glycol yield (61.3%).•30%WOx-C facilitates Ru dispersion and provides rich acid sites.•Reasonable adjustment of acid-metal facilitates ethylene glycol production notably. Ru-WOX composites are usually bi-functional catalysts for cellulose hydrogenolysis, but the proportion/synergism of Ru (metal) and WOX (acidity) are mismatched/unclear, this leads to low ethylene glycol (EG) yield. In this work, we doped Ru‑WOX on low-costed biochar for cellulose hydrogenolysis. The acid-metal balance was adjusted by change the WOX load, and our results show that the activity and EG yield have the order of Ru-30WOX-C > Ru-40WOX-C > Ru-20WOX-C > Ru-10WOX-C, and it is interesting found that a linear relationship between acid/metal ratio and EG yield. Under the optimum conditions (240 °C, 3 MPa and 3 h), Ru-30WOX-C catalyst can achieve 100% cellulose conversion and 61.3% EG yield. 30%WOX facilitates Ru dispersion/reduction, and provides rich acid sites, accompanied by a large number of acid centers (oxygen vacancies), this more easily adsorbed cellulose monomer and activated glucose to glycolaldehyde, and benefit to EG productive. This work provides a guidance to design new bio-functional catalysts for biomass conversion. [Display omitted]