Steam reforming of biomass-derived pyrolysis liquids (bio-oil) to produce hydrogen with carbon-based Ni catalysts is gaining attention due to their advantages in terms of cost, sustainability and activity. However, the
catalytic activity at long times on stream is compromised by either coke deposition or gasification of the support.
To face these drawbacks, two activated carbons have been studied as Ni catalyst support: a microporous carbon
of high purity and a mesoporous carbon with phosphorus surface groups. The activity and long-term stability of
these catalysts have been studied for the steam reforming of model compounds of bio-oil. The microporous
support provided a slightly higher H2 production and lower contribution of methanation reaction. However,
gasification of this support after 20 h led to a decline in the activity, and massive formation of carbon nanotubes
and coke. Nevertheless, the resulting material maintained an outstanding stability with high and stable H2/CO
ratio for 50 h. The P-containing catalyst showed a remarkable long-term stability, but lower H2/CO ratio. Carbon
gasification was less significant in this catalyst due to the presence of surface phosphorus groups, and the
generation of nickel phosphides, which hampers the growth of pyrolytic carbon and carbon nanotubes, leading to
a superior stability
