Biomass gasification
is a promising and sustainable process to
produce renewable and CO
2
-neutral syngas (H
2
and CO). However, the contamination of syngas with tar is one of
the major challenges to limit the deployment of biomass gasification
on a commercial scale. Here, we propose a hybrid plasma-catalytic
system for steam reforming of tar compounds over honeycomb-based catalysts
in a gliding arc discharge (GAD) reactor. The reaction performances
were evaluated using the blank substrate and coated catalytic materials
(γ-Al
2
O
3
and Ni/γ-Al
2
O
3
). Compared with the plasma alone process, introducing
the honeycomb materials in GAD prolonged the residence time of reactant
molecules for collision with plasma reactive species to promote their
conversions. The presence of Ni/γ-Al
2
O
3
gave the best performance with the high conversion of toluene (86.3%)
and naphthalene (75.5%) and yield of H
2
(35.0%) and CO
(49.1%), while greatly inhibiting the formation of byproducts. The
corresponding highest overall energy efficiency of 50.9 g/kWh was
achieved, which was 35.4% higher than that in the plasma alone process.
Characterization of the used catalyst and long-term running indicated
that the honeycomb material coated with Ni/γ-Al
2
O
3
had strong carbon resistance and excellent stability. The
superior catalytic performance of Ni/γ-Al
2
O
3
can be mainly ascribed to the large specific surface area and the
in situ
reduction of nickel oxide species in the reaction
process, which promoted the interaction between plasma reactive species
and catalysts and generated the plasma-catalysis synergy.