Design Of New-Concept Molecularly Imprinted Polymer Catalysts And Their Functional Catalysis

Catalysis is the cornerstone of the modern chemical. Achieving selective catalytic behavior and control of the process is the urgent demand of the times. The new conceptual catalysts based on molecularly imprinted polymers provide an opportunity to the demand. The study prepared two New-Concept Molecularly Imprinted Polymer Catalysts(MIC) with the selective modulation and cascade-reaction properties, which the molecularly imprinted polymer acts as the carrier and the metal nanoparticles as active component which separately equipped with the selective modulation and cascade-reaction properties.Firstly, the study developed selectively commutation Intelligent MIC which is prepared using octane acid as functional monomer, p-nitroaniline(PNA) as template molecule, nickel nitrate hexahydrate as the active ingredient precursors. The whole prepration process includes polymerizaition of the functional monomer, reduction of nickel ions and removal of the template. The catalytic experiments reveal that at the room temperature, PNA substrate molecules can enter the imprinting cavity by the crosslinking network, achieving the selective catalysis with the nickel nanoparticles.However, the analogue of the template nitroaniline can not effectively enter the imprinting crosslinking network, causing the insulation from the nickel nanoparticles.Therefore, intelligent MIC exhibits molecular recognition. In addition, the functional monomer of the catalyst has long carbon chain which develops a space arm after polymerization. As the temperature rises, thermal motion of the space arm is intensified, resulting in the commutation of substrate molecular recognition, achieving selectively modulating catalytic process, which provides a forward-looking reference to complex chemical processes.Besides, the study aims at achieving the “high substrate selectivity, cascade catalytic reaction” MIC reactor, in which the bifunctional molecularly imprinted polymer acts as the carrier, platinum nanoparticles as the active component,p-nitrophenyl acetate(NPA) and p-nitrophenol(NP) as the template.The as-preparedCascade-Reaction MIC contains both with acid center for catalyzed hydrolysis and metal center for hydrogenation. The existence of molecular imprinting carrier makes it possible of the highly selective catalysis. The unique reactor is fabricated with NPA and NP as two well-coupled carrier. The catalytic hydrolysis of NPA results in the formation of NP, which can be further reduced by the encapsulated metal nanoparticles to 4-aminophenol(AP). In this way, Cascade-Reaction MIC achieves successive catalytic processes by bifunctional catalysis. So Cascade-Reaction MIC is a polymer catalyst capable with both the molecular recognition and selective catalytic properties.Therefore, Intelligent MIC and Cascade-Reaction MIC have demonstrated that preparation of the selective polymer catalysts can be realized.