Bio-tar formed during biomass gasification
can cause the blockage
or corrosion of pipelines and devices. Catalytic reforming through
Ni-based catalysts is a potential method to achieve tar elimination,
while carbon deposition is the main obstacle. In this study, the steam
reforming of benzene was investigated over modified Ni/TiO2 catalysts, and the effects of metal promoters, reaction temperatures,
and steam-to-carbon (S/C) molar ratios were explored. The results
indicated that the Fe promoter was promising to simultaneously achieve
the H2-rich gas production and suppress the carbon deposition
over the catalyst. When the reaction temperature was 800 °C and
the S/C molar ratio was 1.00, the benzene conversion ratio and the
H2 yield, respectively, reached 96.31% and 102.53 mmol/gbenzene. Ni–Fe alloys were generated after the modification
with the Fe promoter, which improved the dispersion of Ni components.
Besides, the adsorption of H2O molecules was enhanced which
favored the formation of lattice oxygen and accelerated the reforming
of benzene. Furthermore, the accumulation of lattice oxygen promoted
the oxidation of amorphous carbon and suppressed the formation of
graphitic carbon, thereby protecting the active Ni sites from the
coverage of the carbon layer. Therefore, the resistance of carbon
deposition of the Fe-modified Ni/TiO2 catalyst was improved.