Chemistry Reference
In-Depth Information
OH
OH
OH
O
glyceraldehyde
OH
HO
OH
HO
OH
OH
glyceric acid
O
O
O
HO
OH
tartronic acid
d
n
4
r
4
n
g
|
1
glycerol
O
O
HO
HO
OH
OH
HO
dihydroxyacetone
OH
O
glycolic acid
O
hydroxypyruvic acid
O
HO
OH
O
oxalic acid
Scheme 1.18 Reaction scheme for glycerol oxidation.
O
O
O
O
O
O
O
O
O
OH
O
2,5-diformylfuran
(DFF)
OH
HO
O
5-formyl-2-furancarboxylic acid
(FFCA)
2,5-furandicarboxylic acid
(FDCA)
HO
O
5-hydroxymethylfurfural
(HMF)
O
.
OH
HO
5-hydroxymethyl-2-furancarboxylic acid
(HMFCA)
Scheme 1.19 Reaction scheme for 5-hydroxymethyl-2-furfural oxidation.
bond cleavage and increase the formation of by-products during oxidation
reactions.
The selective oxidation of glycerol by bimetallic Au/Pd and Au/Pt catalysts
supported over MgO at ambient temperature and under base-free conditions
was reported by Hutchings and co-workers.
96
The reactivity at low temperature
under base-free conditions highlighted the activity of PtAu/MgO materials. In
particular, the alloying of Au with Pt leads to the enhancement of both glycerol
conversion and selectivity towards C
3
products compared with Pd.
One of the most important sources of biomass is sugars, which are widely
available and easily transformed. The homogeneous dehydration of glucose
and/or fructose leads to the formation of 5-hydroxymethyl-2-furfural (HMF),
which is a key precursor for the synthesis of chemicals that have applications
in the polymer and pharmaceutical industries.
97-99
In particular, HMF can
be oxidized to 2,5-furandicarboxylic acid (FDCA), which has recently been
proposed as a possible surrogate for terephthalic acid,
100
the monomer used
for the production of terephthalate plastics.
The synthesis of FDCA from HMF has been widely studied in the last two
decades by using different catalysts and reaction conditions. Scheme 1.19
shows the general HMF oxidation pattern. FDCA is generally produced in
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