This paper reports the facile one-pot synthesis of glycidol
via
the transesterification of glycerol with dimethyl carbonate using
KNO
3
/Al
2
O
3
nanoparticles as supporting
catalysts. KNO
3
/Al
2
O
3
nanoparticles
were prepared by the impregnation method. XRD and FT-IR analyses indicated
an interaction between KNO
3
and Al
2
O
3
that enabled the decomposition of KNO
3
during the process
and resulted in the formation of KAl
5
O
8
, the
Al–O–K group, and K
2
O. K
2
O was
recognized as one of the active sites of the catalyst. SEM results
indicated the high performance of the supporting catalyst, as the
catalytic activity depended on both the number of catalytic active
sites and their distribution. The yield of glycidol was 64% at the
expense of 95% glycerol under moderate reaction conditions (120 min,
1 atm, and 70 °C). The nanocatalyst prepared at 800 °C with
a loading amount of 30% KNO
3
was the most efficient for
the synthesis of glycidol. Furthermore, the catalyst was recovered
and reused without a loss of efficiency even after the fourth recycling.
A plausible mechanism for the one-pot synthesis of glycidol has also
been proposed.
In this work we demonstrate one-pot glycidol synthesis, via trans-esterification between glycerol and dimethyl carbonate, by making use of commercially available sodium methoxide as a catalyst. An excellent glycerol conversion (99%) and remarkable glycidol yield (75%) was obtained using dimethyl carbonate/glycerol (molar ratio 2:1) in the presence of 3 wt% catalyst amount (with respect to glycerol weight) at 85 °C for a reaction time of 120 min. Sodium methoxide was recycled and reused twice with only a slight decrease in glycerol conversion. The water content of the glycerol reached 2.5 wt%; this did not reduce the glycerol conversion efficiency of the catalyst. A plausible mechanism for the trans-esterification involved in the preparation of glycidol was proposed.
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