High dispersed Ru/SiO2-ZrO2 catalyst prepared by polyol reduction method and its catalytic applications in the hydrodeoxygenation of phenolic compounds and pyrolysis lignin-oil.

• High dispersed Ru/SiO 2 -ZrO 2 catalyst was prepared by polyol reduction method. • Ru/SiO 2 -ZrO 2 exhibited an efficient HDO performance of pyrolysis lignin-oil. • Hydrocarbon content in lignin-oil increased to 86.1% from 16.2% after upgrade. • High Ru dispersion and strong acid sites resulted in high catalytic HDO activity. • Synergetic catalysis of Ru and acid sites also promoted the occurrence of HDO. Metal particle size and metal dispersion significantly influence the catalyst activity, and an efficient catalytic upgrade of bio-oil to high-quality liquid fuel is always difficult. Herein, a high dispersed Ru/SiO 2 -ZrO 2 catalyst was prepared by polyol reduction method, which exhibited a high catalytic activity on hydrodeoxygenation (HDO) of the phenolic compounds and pyrolysis lignin-oil. As a model compound, guaiacol had a conversion of 99.9% and a cyclohexane selectivity of 96.7% at the temperature of 240 °C. This polyol Ru/SiO 2 -ZrO 2 catalyst had a good recyclability in the guaiacol HDO. No significant decrease on the catalytic activity was presented after continuous 5 runs, and the conversion kept close to 100% and the selectivity of cyclohexane kept above 88%. Several common phenolic compounds also enabled to be turned into corresponding cycloalkanes efficiently. The high Ru dispersion and the large amount of strong acid sites in the polyol Ru/SiO 2 -ZrO 2 are the main reasons for the good catalytic performances. The synergetic effects between high dispersed metal site and strong acid site lead to a promoted efficiency in the HDO process to form the cycloalkanes. This active catalyst was also applicable to the upgrade of pyrolysis lignin-oil. After reaction, the content of hydrocarbons in the lignin-oil increased from 16.2% to 86.1%, and guaiacols and other oxygenated compounds were almost disappeared. The upgraded lignin-oil has potential to be used as high-quality fuels directly. [ABSTRACT FROM AUTHOR]