Tar formation is an urgent issue to be addressed during biomass gasification, and it is highly efficient to apply the cheap catalyst (e.g., Ni-based catalyst) in the process. Herein, we have developed a series of novel Ni/(Mg, Al)O_x catalysts derived from Ni-Mg-Al hydrotalcites and realized high conversion of real tar and tar model. Among the designed catalysts, Ni/MAO catalyst prepared at pH of 10 and aging temperature of 20 °C (Ni/MAO-10) exhibited superior activity in toluene conversion (95.3%) and syngas production (833 mmol/g-Ni), as well as the excellent resistance to carbon deposition. Through characterizations, the highest basicity, highest reducibility, tailored “rosette-like” morphology, and larger specific surface area in Ni/MAO-10 were confirmed. Furthermore, the structure-activity relationship, reforming mechanism, deactivation, and regeneration of the catalyst were comprehensively elaborated from rigorous experiments, and meanwhile, the activation energies and turnover frequency (TOF) values of these Ni/MAO catalysts in the reforming of real tar and tar model compound were calculated to theoretically explain their activities.

Biomass tar; Catalytic reforming; Ni-based catalyst; structure-actvitiy relationship