Direct synthesis of dimethyl carbonate and propylene glycol using potassium bicarbonate as catalyst in supercritical CO₂

Abstract

The improved one-pot synthesis of dimethyl carbonate and propylene glycol from propylene oxide, supercritical carbon dioxide, and methanol with potassium bicarbonate as the catalyst has been reported in this paper. As far as we know, it is the fi rst time to use potassium bicarbonate only as the catalyst in the production process which is simple and cheap. Satisfactory conversion rate of propylene oxide and yield of the products could be achieved at the optimized conditions with quite a small amount of by-products. Our new method offers an attractive choice for the production of dimethyl carbonate in large-scale industry effi ciently and environmental friendly.

Dehydrating agent effect on the synthesis of dimethyl carbonate (DMC) directly from methanol and carbon dioxide

“…3.1 Direct synthesis of DMC using molecular sieve (3A) and combination of dehydrating agents Thermodynamic limitations and/or catalyst deactivation due to water formation during DMC direct synthesis makes this reaction unfavorable resulting in low DMC yield. 5,24,25 Aiming to evaluate the effect of dehydrating agents (chemical or physical) on the yield of DMC obtained by direct synthesis reaction CH 3 OK was used as catalyst and CH 3 I as promoter. Table 1 presents methanol conversion, DMC selectivity and DMC yield values, reaction parameters and Tukey test results used to evaluate statistical equality between samples (see letters a to g in conversion column, Table 1).…”

CeO2-Decorated α-Fe2O3 Nanorings for the Direct Synthesis of Dimethyl Carbonate from CO2 and Methanol

“…However, this synthetic route presents thermodynamic limitations, and the use of dehydrating agents must be employed in order to shift the equilibrium . Several homogeneous and heterogeneous catalysts have been studied to convert CO 2 and methanol into DMC, including AC-Fe (iron salts impregnated on activated carbon), Cu–Ni/graphene, K 2 CO 3 , − and metal oxides, such as ZrO 2 , Fe 0.7 Zr 0.3 O y , and CeO 2 , , among others.…”

“…Many metal oxide nanomaterials have been considered as efficient heterogeneous catalysts for the direct synthesis of DMC from CO 2 and methanol. Thus, CeO 2 is an exciting choice because of its high density of basic sites, high oxygen storage capacity (OSC), oxygen mobility, and good redox properties, which render excellent catalytic properties for DMC production. ,− We have demonstrated that different cerium precursors influence the morphology of the synthesized nanostructured CeO 2 , modifying the exposed planes, basicity, and concentration of oxygen vacancies . This later property also plays a crucial role in the catalytic activity of DMC production from CO 2 and methanol. − However, pure CeO 2 presents poor thermal stability and readily sinter at high temperatures. , Thus, ceria-supported catalysts are preferred over individual components due to their combined properties, enabling them to overcome the limitations of single-phase materials. , Reports have shown that adding transition metal oxides into the CeO 2 structure improves the catalytic performance of the mixed oxides compared to the bare ones. , For example, Tomishige et al observed an improvement in thermal stability and redox properties upon adding ZrO 2 to the CeO 2 structure for the DMC synthesis.…”

Performance of supported metal catalysts in the dimethyl carbonate production by direct synthesis using CO2 and methanol

“…•[89]. Diffraction peaks around 59 • and 62.5 • correspond to (511) and (440) planes of Fe 3 O 4[88,[90][91][92][93]. Besides, a peak near 25• corresponds to goethite (120) (JCPDS Card n • .…”