Ionic Liquid/Zn-PPh₃ Integrated Porous Organic Polymers Featuring Multifunctional Sites: Highly Active Heterogeneous Catalyst for Cooperative Conversion of CO₂ to Cyclic Carbonates

Abstract

A series of ionic liquid (IL), zinc halide (ZnX 2 ), and triphenylphosphine (PPh 3 ) integrated porous organic polymers (POPs) featuring multifunctional sites were afforded through solvothermal synthesis for cyclic carbonate synthesis which utilizes epoxides and carbon dioxide (CO 2 ). Owing to the cooperative effect of ionic liquid and homogeneously distributed Zn-PPh 3 specie, which is probably strengthened by the confined microporous structure and flexible frameworks, these POPs catalysts exhibited high CO 2 capture and conversion performance and provided the highest activity (initial turnover frequencies up to 5200 h −1 ) of heterogeneous catalysts reported to date within the context of cyclic carbonate formation. Even more surprising, very favorable turnover numbers (TONs) of 2120 and 720 were attained at 40 and 25 °C, respectively. The effect of reaction parameters (reaction time, temperature, CO 2 pressure) on the catalytic performance as well as other epoxide substrates were also investigated in detail. Furthermore, the catalyst can be easily recovered and reused five times without a significant loss of activity. These ionic liquid and Zn-PPh 3 constructed porous polymers may provide an industrial opportunity for cyclic carbonate products.

Highly Efficient and Convenient Supported Ionic Liquid TiCl5-DMIL@SiO2@Fe3O4-Catalyzed Cycloaddition of CO2 and Epoxides to Cyclic Carbonates

“…From these results, a possible reaction mechanism using the cycloaddition of propylene oxide with CO 2 as an example is proposed and depicted in Scheme 3 based on the previous literatures [12,13,[34][35][36][37] and the observations in this reactions. At first, the substrate epoxide is activated by TiCl 5 -DMIL@SiO 2 @Fe 3 O 4 to form the complex 1 by the coordination of one TiCl 5 anion with O atom of propylene oxide.…”

“…Examples of their applications in the synthesis of cyclic carbonates from CO 2 and epoxides were reported [33][34][35][36][37]. Although their good catalytic activities in the reaction, they have some problems such as partially ILs wasted and difficulties in separating catalysts from products after the reaction.…”

Sustainable Cyclic Carbonate Production, Utilizing Carbon Dioxide and Azolate Ionic Liquids

“…[36][37][38][39][40][41][42] Some key processes, to date, using homogenous ionic liquid systems are summarised in Table 1. It is noteworthy, that there have also been a number of solid-supported ionic liquid systems [41][42][43][44][45][46] employed for producing cyclic carbonates. Though they produce high yields of products, these systems also contain undesirable halides and/or metals.…”

Iridium Supported on Phosphorus‐Doped Porous Organic Polymers: Active and Recyclable Catalyst for Acceptorless Dehydrogenation and Borrowing Hydrogen Reaction

“…[2] Therefore, POPs possess high specific surface areas, thus enabling their excellent thermal and chemical stability, and the ability to endure harsh reaction conditions. In the recent years, a series of metals that were supported on POPÀ PPh 3 or other derivatives, have been reported, [3] including rhodium, [4] platinum, [5] cobalt, [6] iron, [7] molybdenum, [7] zinc [8] and gold. [3] It was observed that introducing PPh 3 could create high density of ligand sites in the POPs, which led to increased loading stability and capability of the active metals and enhanced capability of catalyst recovery.…”

“…[9] Recently, Zhang and Zhuang described a synthesis of novel phosphorus-containing hyper-crosslinked porous polymer (HC-TVP) from tris (4-vinylphenyl) phosphane through radical polymerization. [8] In 2017, Zhan and Ding developed a P-doped porous organic polymer and employed it as support and ligand to achieve a novel Pd complex which has shown high efficiency in catalyzing hydrogenation reactions and resulted in high chemoselectivity. [7] Later, Shi and Ma discovered that triazoleÀ gold(I) complex could be anchored into porous organic polymer to enhance the stability and reactivity of gold(I) catalyst.…”