The study of coke resistance of Ni/ZrO2 by core-shell structure coupling with cobalt doping modification in CO2 reforming of tar

Abstract

The issue of loaded Ni/ZrO2 catalyst deactivation has limited the further development of biomass tar reforming. To reduce sintering and coke deposition by optimizing the catalyst, the effects of core-shell structure and cobalt doping coupling on coke deposition in Ni/ZrO2 catalyst are investigated. The Ni/ZrO2 catalyst was deactivated by coke deposition and sintering after 150 min of CO2 reforming of tar. The Ni8Co/ZrO2 @SiO2 catalyst exhibited high stability and efficiency of hydrogen conversion (CH) (50–67 %) and carbon conversion (CC) (40–60 %) in the toluene reforming, and the CH (65–81 %) and CC (73–100 %) in the acetone reforming within 300 min due to the larger specific surface area and richer pore structure. The characterization on the used catalysts showed that only filamentous coke without encapsulated coke was observed after the reforming of different type of tars reaction. The Ni8Co/ZrO2 @SiO2 catalyst yielded only 6 % and 0.2 % filamentous coke after toluene and acetone reforming reactions.