This study investigates the influence of ionic liquid in morphology, acid-base properties, metal dispersion and performance of 5%Ni/ZrO2 catalysts in the methane tri-reforming reaction. Zirconia was prepared by precipitation and the catalysts by wet impregnation. The ionic liquid modified the acid and basic character of the catalysts and positively influenced the methane tri-reforming reaction efficiency. The reaction was evaluated with synthetic biogas and with stoichiometric feed molar ratio (CH4: CO2: H2O: O-2 = 1:0.5:0.5:0.1 and CH4: CO2: H2O: O-2 = 1:0.33:0.33:0.16). The Ni/ZrO2 prepared with ionic liquid exhibits promising catalytic activity and stability in methane tri-reforming at 800 degrees C in 4 h run, without coke formation. An increase in the reaction temperature results in an increase of hydrogen yield and the methane conversion, reaching similar to 85% at 850 degrees C. The presented results demonstrate that the tri-reforming reaction could be used for production of syngas with H-2/CO ratio appropriate for methanol synthesis. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.