The synthesis of spherical polymeric ionic liquid catalyst and
its catalysis for CO2 to dimethyl carbonate by one-pot
methods
Wenqiang Liu , Yajuan Wang ,Juan Zhang* Jiangxin Li
College of Chemical and Pharmaceutical Engineering, Hebei University of
Science and Technology, 26 Yuxiang Street, Shijiazhuang, 050018,
P.R.China
*Corresponding author. E-mail address:
mytomorrow@126.com (J Zhang)
Abstract: Dimethyl carbonate (DMC)
is widely used and nontoxic and can replace more dangerous materials
such as dimethyl sulfate or methyl chloride. Spherical particle
catalysts (PILs-XSS) were synthesized by suspension polymerization,
which was characterized by SEM-EDS, FT-IR, TG, and BET-BJH. The
characterization results showed that PILs-XSS had a specific core
structure, a certain pore size (14.3nm), and surface area size
(71.5m2/g), and remained stable at 293.4 °C. The
catalyst performance was evaluated by a one-pot synthesis of dimethyl
carbonate. The process conditions were optimized in detail. The optimal
reaction conditions were as follows: the dosage of PILs-XSS was 2.5 wt
%, the CO2 pressure was 1.5 MPa, the reaction
temperature was 100 °C, the reaction time was 4 h, the molar ratio of
methanol to propylene oxide (PO)was 3: 1, and the dosage of cocatalyst
Na2CO3 was 3 wt %. Under the optimum
conditions, the conversion of PO was up to 98.8 % and the yield of DMC
reached 53.7 %. In addition, the combined catalyst
PILs-Na2CO3 was easily recovered by
filtration in the reaction system. After five times of repeated use, the
activity and the shape of the catalyst were almost unchanged, which
meant that the catalyst had amazing mechanical strength. This study
found that the transesterification catalyst
Na2CO3 not only had good
transesterification efficiency but also promoted the reaction of
CO2.
Keywords: Poly-ionic liquid, CO2, Dimethyl
carbonate, Propylene oxide