Synthesis of Propylene Carbonate from Carbon Dioxide and Propylene Oxide Using Zn-Mg-Al Composite Oxide as High-efficiency Catalyst

Abstract

A series of Zn-Al composite oxides that were modified with alkaline earth metals, Zn-M-Al-O (M = Mg, Ca, Sr, and Ba) were fabricated via calcination of the corresponding hydrotalcite precursors, and evaluated as catalysts for the synthesis of propylene carbonate (PC) from CO 2 and propylene oxide. Among the Zn-M-Al-O catalysts, Zn-Mg-Al-O (Zn/Mg = 4.0, pH = 10, without hydrothermal treatment) is the best in performance, showing PC selectivity of 99.2% and yield of 88.8% (140°C, 12 h). Furthermore, the Zn-Mg-Al-O catalyst can be readily reused and recycled without any loss of activity in a test of five cycles. Through detailed studies of the basic nature of the Zn-M-Al-O catalysts, it was found that a moderate basicity (6.1 B H 0 \ 8.9) is beneficial to the cycloaddition reaction. The NH 3 -and CO 2 -TPD results also indicate that the Zn-Mg-Al-O catalyst has acid-base bifunctional properties, and a reaction mechanism is proposed.

High-Efficiency Synthesis of Cyclic Carbonates from Epoxides and CO2 over Hydroxyl Ionic Liquid Catalyst Grafted onto Cross-Linked Polymer

“…Over the copolymer of 3-butyl-1-vinylimidazolium chloride with cross-linker divinylbenzene (PSIL) reported by Xie et al [33], PC yield and selectivity are 74.9 and 99.1%, respectively (Table 1, entry 10). Over Zn-Mg-Al composite oxide reported by us [42], PC yield and selectivity are only 55.4 and 97.2% (Table 1, entry 11). In other words, PDVB-HEIMBr is superior to the two catalysts in performance.…”

“…For comparison, the performance of a couple of known catalysts [33,42] under equal reaction conditions are listed in Table 1. Over the copolymer of 3-butyl-1-vinylimidazolium chloride with cross-linker divinylbenzene (PSIL) reported by Xie et al [33], PC yield and selectivity are 74.9 and 99.1%, respectively (Table 1, entry 10).…”

Using carbon dioxide and its sulfur analogues as monomers in polymer synthesis

“…Numerous catalyst systems with significant advances have been discovered for CO 2 /epoxide coupling reaction in recent decades. Heterogeneous catalysts such as metal oxides [55][56][57], zeolite and its supported catalysts [58,59,145,146] were utilized to catalyze CO 2 /epoxide coupling reaction. Homogeneous catalysts such as amines and phosphines [147,148], alkali metal halides [149], metal-salen complexes [150,151], metal porphyrins [152,153], and transition metal complexes [154][155][156] were also extensively investigated.…”

“…The synthetic methods for CO 2 -based polymers with various topologies [44][45][46][47][48][49][50][51][52][53][54], which emerges as new directions in C1 copolymerization field, will be presented based on recently published works for their potential applications. Cyclic carbonates, which could be prepared from the coupling reaction of CO 2 with epoxides (and epoxy resins), are important intermediates for synthesizing poly(hydroxyl urethane)s [55][56][57][58][59][60][61]. It is a new non-isocyanate route to make new polyurethanes and will be discussed with recent progress.…”

Guanidine Hydrochloride/ZnI2 as Heterogeneous Catalyst for Conversion of CO2 and Epoxides to Cyclic Carbonates under Mild Conditions

“…Also cyclic carbonates can be widely applied in proton inert solvents, as precursors for polycarbonates and polyurethanes synthesis, as electrolytes in lithium secondary batteries, and as intermediates for production of pharmaceuticals, fine chemicals and agricultural chemicals [4,5]. So far, numerous homogeneous and heterogeneous catalysts for this transformation have been reported, including metal-oxides [6,7], alkali metal salts [8], organometallic complexes [9], organic bases or ammonium/phosphonium salts [10][11][12], N-heterocyclic carbenes [13], modified molecular sieves [14,15] and ionic liquids [16][17][18]. Nevertheless, homogeneous catalysts are undesirable in industry due to problems such as rigorous separation and purification of the products.…”