This study investigated the catalytic activities of sulfided Ni/W/TiO2 (anatase) catalysts for the hydrodeoxygenation (HDO) of guaiacol (2-methoxyphenol), which is a model compound for bio-oils derived from lignocellulosic biomass. The HDO activity of the catalysts was governed by the physicochemical states of the tungstate layer and the sulfides on the surface. We observed that the molecular structure of tungstate, the sulfidation degree of the tungstate layer and the number and intrinsic activity of sulfur sites are the crucial factors that determine the HDO activity of sulfided Ni/W/TiO2 (anatase) catalysts. The best activity was observed for sulfided 2 wt.% Ni/12 wt.% W/TiO2 (anatase), which exhibited 100% guaiacol conversion and a 16% C-1-based yield of cyclohexane. (C) 2014 Elsevier B.V. All rights reserved.