the monometallic Pd/C catalyst was more active than the bimetallic one, while
Pd-Ir 0.1 /C was more selective towards the formation of the unsaturated alcohol.
Therefore, the incorporation of a small amount of Ir (0.1 equiv.) on the Pd surface
is able to modify the nanoparticle catalytic selectivity.
Another
recent
example
is
the
catalytic
transformation
of
5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) over bimetallic PtIr
NPs supported on a mesoporous carbon material, CMK-3, described by Beltramone
et al. (Fig. 8) [101]. While the monometallic catalyst (Pt-CMK-3) gave 50%
selectivity towards DMF at 90% conversion, the bimetallic one (PtIr-CMK-3)
showed a higher activity/selectivity (86% at 98% conversion). In conclusion, they
observed that the PtIr alloy catalyst is more active and selective towards the
formation of 2,5-DMF than the analogous Pt catalyst, due to a synergistic effect
between Ir and Pt.
Two-dimensional carbon-based materials like graphene, graphene oxide or
reduced graphene oxide are being widely used for the deposition of MNPs
Fig. 8 Reaction scheme for the hydrogenation/hydrodeoxygenation of hydroxymethylfurfural
(HMF). Reprinted with permission from Ref. [101]. Copyright 2019 Elsevier
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