Furfural hydrogenation to furfuryl alcohol is an industrially
significant
reaction for biomass valorization. The hydrogenation process has been
mainly catalyzed by chromite-based materials that are notorious for
their toxicity, thereby highlighting the need to find alternate catalyst
materials. In addition, there is a gap in the mechanistic understanding
of furfural hydrogenation on transition metal surfaces. Herein, we
combine density functional theory calculations and microkinetic modeling
to study the reaction mechanism of furfural hydrogenation to furfuryl
alcohol on terrace (111/0001) and stepped (211) transition metal surfaces.
We find that the rate-determining steps for furfural hydrogenation
depend on the identity of the metal, where the strong binding metals
are limited by desorption of the product (furfuryl alcohol), while
the moderate and weak binding metals are limited by steps involving
surface hydrogenation or H2 activation. We show that the
binding energy of furfural is a good descriptor to rationalize and
predict the activity trends for the production of furfuryl alcohol.
Among the metal and bulk/single atom alloy surfaces investigated in
this work, we find Cu-based alloys to be the most active catalysts,
with Cu-rich CuNi alloys predicted to be promising candidates for
furfural hydrogenation.