Biochar obtained from microwave pyrolysis of corn stalk was employed for catalyzing tar reforming, using toluene as the representative. Catalytic performance of different biochar and toluene reforming with a mixed agent of CO2 and H2O were focused on. By comparison, it was found Fe-doped activated char exhibited a relatively steady capability on toluene CO2 reforming, with an average conversion of 94.3% in whole test of 150 min. This was due to this char had a large surface area of 321.2 m(2)/g and the advanced pore structure. The other reason to this was the formation of pure iron and iron carbide during toluene reforming. Synergetic effect arose in toluene combined reforming was validated, through comparing the actual conversion from combined reforming with the weighed conversion from two individual reforming with CO2 or H2O. Synergetic effect was influenced by temperature and it was highlighted at 800 degrees C, with a mean conversion of 94.8% within a test of 150 min. Meanwhile, increasing molar ratio of CO2 to H2O could enable the strength of synergetic effect. At the biggest ratio of 2:1, the actual conversion from toluene combined reforming was 12.3% higher than the weighed conversion from two single reforming. (C) 2019 Elsevier Ltd. All rights reserved.