Facile synthesis of Ni-doped zeolite-based catalysts from waste coal gasification fine slag for steam reforming of toluene

Abstract

The preparation of efficient and stable catalysts for biomass tar reforming using low-cost solid waste is of great value for achieving green biomass gasification. In this work, new porous Ni-doped zeolite catalysts were formed by an ion exchange method making use of the waste CGFS as the precursor. At a proper NiO loading content, the catalyst (Na@Air-0.2Ni) exhibits a uniform spherical particle-linked porous structure with NaAlSiO4 as the supporting matrix and NiO particles anchoring on the surface as active sites. The catalytic performance of the catalysts was investigated in toluene reforming experiments to evaluate their potential for biomass tar conversion. Under optimized conditions (720 °C, S/C = 1.5, and N2 flow 25 mL/min), toluene conversion reached 92 % using Na@Air-0.2Ni as a catalyst, yielding 2500 μmol/min CO and 2800 μmol/min H2. Continuous steam reforming of toluene formed to FeNi3 alloy, which in turn strengthens the stability of the catalyst, and a high toluene conversion of 81 % can be achieved in 450 min continuous experiment, indicating the excellent stability of the catalyst. This work has confirmed that coal gasification slag rich in silicon and aluminum has the potential to prepare new zeolite-based catalysts, which is an important exploration for promoting high-value conversion of solid waste.