Upgrading syngas from wood gasification through steam reforming of tars over highly active Ni-perovskite catalysts at relatively low temperature

Tar formation during biomass gasification causes several operational problems, besides limiting the downstream application of the syngas produced. The development of an efficient catalyst for tar reforming at mild temperature is targeted. In this study, La-based perovskite (La0.6Sr0.4Co0.2Fe0.8O3-δ)-supported Ni materials have been synthesized through wetness impregnation (Ni/LSCF) and one-pot sol-gel method (Ni-LSCF). As-prepared catalysts have been characterized by N2 physisorption, XRD, TPR, H2-TPD and XPS. The impact of the synthesis path and the effect of Ru have been evaluated in steam reforming of toluene and phenol at low temperature (550 °C) under a model syngas. Regardless the tar model molecule, similar catalytic stability and activity toward tar reforming were attained for both Ni/LSCF and Ni-LSCF. However, a better catalytic performance toward WGS and higher resistance to coke formation were evidenced for Ni-LSCF than for Ni/LSCF. This better behavior has been mainly ascribed to the high Sr content at its surface, pointing out the key role of the basic elements at the catalytic surface in the activity and stability in steam reforming of tars. The addition of Ru led to an enhancement in the catalytic activity for toluene reforming, while no noticeable improvement was attained for phenol reforming.