328
J. A. Delgado and C. Godard
+
285 ºC, 45 min.
PdNPs
Pd(acac) 2
HO
2-methyl-3-butyn-2-ol
(MBY)
HO
H 2
2-methyl-3-buten-2-ol
(MBE)
Fe 3 O 4 / -Fe 2 O 3
Oleylamine
Oleic acid
Dioctyl ether
Fe 3 O 4 / -Fe 2 O 3
X= 95%
S C=C = 96%
Fig. 10.14 Synthesis of Pd/FeO x NPs and their application in the semi-hydrogenation of 2-methyl3-butyn-2-ol (MBY)
The reduction of the parent material (Pt/In 2 O 3 ) under defined temperatures permitted
the selective poisoning of edge and corner sites of Pd nanoparticles by reduced In
atoms which resulted in a remarkable enhancement of the alkene selectivity in the
semi-hydrogenation of relevant molecules such as dehydrolinalool when compared
with a non-poisoned catalyst (95 vs. 89% at 99% of conversion).
As a strategy for recycling colloidal catalyst based on Pd, hybrids with iron oxide
moieties have been reported as easily recoverable catalysts by simply using magnetic
fields. For instance, Bronstein et al. reported the deposition of Pd NPs on preformed
iron oxide NPs and their application in the semi-hydrogenation of 2-methyl-3-butyn2-ol [151]. Interestingly, the hybrid Pd/FeOx catalyst displayed a higher activity
compared to the monometallic Pd NPs (95 vs. 6% conversion), without affecting the
alkene selectivity (96%, Fig. 10.14). The authors attributed this result to a possible
electron transfer from the iron oxide NPs towards the Pd NPs.
Following an analogous approach, Uberman et al. studied the application of
a recoverable catalyst made of PdNPs deposited on a colloidal magnetic support
(silica-coated magnetite functionalized with amido groups, FFSiNH 2 ) in the semihydrogenation of 3-butyn-1-ol [152]. The hybrid material evidenced moderate to
good selectivity under mild conditions (82% at 98% conversion). Corma et al. demonstrated that semi-hydrogenation of alkynes is possible by using merely small iron
oxide NPs (either Fe 2 O 3 or FeO) deposited on slightly acidic inorganic oxides (e.g.
nanosized ZnO, TiO 2 , ZrO 2 ,) [153]. In spite of the simplicity of concept, this material provided good performance in the semi-hydrogenation of alkynes in liquid phase
and acetylene in ethylene-rich mixtures.
J. A. Delgado and C. Godard
+
285 ºC, 45 min.
PdNPs
Pd(acac) 2
HO
2-methyl-3-butyn-2-ol
(MBY)
HO
H 2
2-methyl-3-buten-2-ol
(MBE)
Fe 3 O 4 / -Fe 2 O 3
Oleylamine
Oleic acid
Dioctyl ether
Fe 3 O 4 / -Fe 2 O 3
X= 95%
S C=C = 96%
Fig. 10.14 Synthesis of Pd/FeO x NPs and their application in the semi-hydrogenation of 2-methyl3-butyn-2-ol (MBY)
The reduction of the parent material (Pt/In 2 O 3 ) under defined temperatures permitted
the selective poisoning of edge and corner sites of Pd nanoparticles by reduced In
atoms which resulted in a remarkable enhancement of the alkene selectivity in the
semi-hydrogenation of relevant molecules such as dehydrolinalool when compared
with a non-poisoned catalyst (95 vs. 89% at 99% of conversion).
As a strategy for recycling colloidal catalyst based on Pd, hybrids with iron oxide
moieties have been reported as easily recoverable catalysts by simply using magnetic
fields. For instance, Bronstein et al. reported the deposition of Pd NPs on preformed
iron oxide NPs and their application in the semi-hydrogenation of 2-methyl-3-butyn2-ol [151]. Interestingly, the hybrid Pd/FeOx catalyst displayed a higher activity
compared to the monometallic Pd NPs (95 vs. 6% conversion), without affecting the
alkene selectivity (96%, Fig. 10.14). The authors attributed this result to a possible
electron transfer from the iron oxide NPs towards the Pd NPs.
Following an analogous approach, Uberman et al. studied the application of
a recoverable catalyst made of PdNPs deposited on a colloidal magnetic support
(silica-coated magnetite functionalized with amido groups, FFSiNH 2 ) in the semihydrogenation of 3-butyn-1-ol [152]. The hybrid material evidenced moderate to
good selectivity under mild conditions (82% at 98% conversion). Corma et al. demonstrated that semi-hydrogenation of alkynes is possible by using merely small iron
oxide NPs (either Fe 2 O 3 or FeO) deposited on slightly acidic inorganic oxides (e.g.
nanosized ZnO, TiO 2 , ZrO 2 ,) [153]. In spite of the simplicity of concept, this material provided good performance in the semi-hydrogenation of alkynes in liquid phase
and acetylene in ethylene-rich mixtures.