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. 2008 Jun 26;37(8):1619–1628. doi: 10.1039/b716441f

Table 2. Summary of the bimetallic DENs as catalysts.

Metal system Synthetic route a Composition of DENs Structure of DENs Average diameter/nm Catalyzed reaction Property Ref.
RuRh C G5-Q(Ru x Rh y ) Alloy ca. 1.0 Hydrosilylation >98.8% b 25
Hydrogenation c
PdAu C G6-Q116(Pd n Au150–n ) Alloy ca. 1.8 Allyl alcohol 70–200% (m) 16
S G6-Q116[Au55](Pd n ) Core/shell 1.8–2.3 Allyl alcohol 30–38% (Pd) 16
S G6-OH[Pd55](Au n ) Core/shell 2.4–2.9 Allyl alcohol Precipitation 16
PdPt C G4-OH(Pd x Pt40–x ) Alloy ca. 2.1 Allyl alcohol 30–50% (m) 15
PdPt C G4-OH(Pd x Pt y ) Alloy ca. 2.3 1,3-Cyclooctadiene 45–50% (m) d 14,23
PdRh C G4-OH(Pd x Rh y ) Alloy ca. 2.3 1,3-Cyclooctadiene 75–120% (m) d 14,27
PdPt C,S Gn-OH(Pd x Pt y ) 3,4-Epoxy-1-butene Enhanced e 26
PtRu C,S Gn-OH(Pt x Ru y ) 3,4-Epoxy-1-butene Enhanced e 26
Oxidation f
PdAu C G4-NH2(Pd27.5Au27.5) Alloy ca. 1.8 CO 35 °C (Pd) 17
PtAu g TD G5-OH(Pt16Au16) Alloy <3.0 CO 2 (Pt), 8.5 (c) 32
PtCu g C G5-OH(Pt23Cu23) Alloy <3.0 CO 2 (Pt) 44
PtCu C G4-OH[Pt x ](Cu y ) Core/shell <3.0 CO 30
Reduction
PdPt C G6-OH(Pd x Pt y ) Alloy ca. 1.8 O2 2.4 (Pt) h 47
PtAu E G4-NH2(Pt x Au y ) Alloy O2 Good 48
Application
AuAg C G6-OH(Au27.5Ag27.5) Alloy ca. 1.5 No 28
S G6-OH[Au55](Ag n ) Core/shell ca. 1.9 No 28
C,S G6-OH[AuAg]55(Au n ) Core/shell 1.5–2.7 No 28
AgM t i PD Gn-OH(Ag x M t y ) Alloy No 18
PD Gn-OH[Ag x ](M t y ) Core/shell No 18
CuM t i PD Gn-OH(Cu x M t y ) Alloy No 18
PD Gn-OH[Cu x ](M t y ) Core/shell No 18
CuAg PD Gn-OH(Cu x Ag y ) Alloy No 18
PD Gn-OH[Cu x ](Ag y ) Core/shell No 18

a C = Co-complexation, S = Sequential loading, PD = Partial displacement reaction, TD = Total displacement reaction, E = Electrodeposition.

b The conversion of Si–H.

c Enhanced percentage in turnover frequency compared to the monometallic DENs and their physical mixture (denoted m) in brackets.

d The selectivity at the complete conversion of 1,3-cyclooctadiene was higher than 99%.

e Bimetallic DENs enhanced the catalytic activity of the selective hydrogenation (in some cases) compared with materials prepared from traditional wet impregnation of metal salts.

f PdAu catalyst prepared using G4-NH2(Pd27.5Au27.5) lowered temperature of complete (100%) CO conversion compared to that of Pd catalyst prepared via G4-NH2(Pd55) (in PdAu system), relative rate times of Pt16Au16 to those of Pt32 and co-metallic Pt32 + Au32 (denoted c) catalysts at 100 °C (in PtAu system), and relative rate times of Pt23Cu23 to that of Pt45 catalyst at 60 °C (in PtCu system).

g PtAu and PtCu alloy catalysts were obtained by removing G5-OH using thermolysis treatment.

h Relative factor in electrocatalytic activity compared to monometallic Pt DENs in brackets.

i M t = Au, Pt, and Pd.