Reaction Environment Modification in Covalent Organic Frameworks for Catalytic Performance Enhancement

Abstract

Herein, we show how the spatial environment in the functional pores of covalent organic frameworks (COFs) can be manipulated in order to exert control in catalysis. The underlying mechanism of this strategy relies on the placement of linear polymers in the pore channels that are anchored with catalytic species, analogous to outer‐sphere residue cooperativity within the active sites of enzymes. This approach benefits from the flexibility and enriched concentration of the functional moieties on the linear polymers, enabling the desired reaction environment in close proximity to the active sites, thereby impacting the reaction outcomes. Specifically, in the representative dehydration of fructose to produce 5‐hydroxymethylfurfural, dramatic activity and selectivity improvements have been achieved for the active center of sulfonic acid groups in COFs after encapsulation of polymeric solvent analogues 1‐methyl‐2‐pyrrolidinone and ionic liquid.

Poly(ionic liquid) composites

“…71 Inspired by the improved performance from the ''ship in a bottle'' strategy for producing PIL-MOF composites, other nanoporous materials, e.g., COFs and porous membranes, were also utilized as hosts for PIL. 72 Kang and coworkers in situ polymerized a 1,4-bis[3-(2-acryloyloxyethyl)imidazolium-1-yl]butane TFSI monomer in a 1-ethyl-3-methylimidazolium TFSI (EMITFSI)-based electrolyte within a PDADMA-TFSI porous membrane. The well-designed hierarchical composites were used as solid electrolytes and they exhibited superior cycling performance with high specific capacities.…”

Recent Advances in Covalent Organic Frameworks for Catalysis

“…[73][74][75][76][77] Generally,i ncorporating nitrogen-containingm olecular units, such as amine, imine and triazine groups, within at unable COF could facilitatet ol ock metal active sites. [73][74][75][76][77] Generally,i ncorporating nitrogen-containingm olecular units, such as amine, imine and triazine groups, within at unable COF could facilitatet ol ock metal active sites.…”

“…To the best of our knowledge,m ultifunctional COFs polymers possess high potentials as efficient robustc atalystsa nd have been widely utilized in different types of organic chemical reaction. [73][74][75][76][77] Generally,i ncorporating nitrogen-containingm olecular units, such as amine, imine and triazine groups, within at unable COF could facilitatet ol ock metal active sites. Thus the heterogeneous functionalized catalysts rooted in covalent polymer carriers display high activities and are also easily to be recovered and reused.…”

Several alternative strategies for non-green polar aprotic solvents

“…在上述反应中, 他们均没 图 3 溶剂片段功能化的苯乙烯基聚合物单体 [14] (网络版 彩图) Figure 3 Structures of vinyl-functionalized solvent moieties [14] (color online). 图 4 酸性COF材料极性微环境修饰方法 [15] (网络版彩图) Figure 4 The concept of modification of the local reaction environment of active sites on acid COFs [15] (color online).…”