Highly Dispersed DPPF Locked in Knitting Hyper‐Crosslinked Polymers as Efficient and Recyclable Catalyst

Abstract

In this study, a novel catalytic system based on the hyper-crosslinked 1,1'-Bis (diphenylphosphino) ferrocene (HCP-DPPF) is prepared for effectively removing Cr (VI) from water. Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM) and X-ray Photoelectron Spectroscopy (XPS) were employed for the characterization of the catalyst. The surface area of HCP-DPPF can reach 349.7 m 2 g À1 and the SEM mapping shows that Fe has a good dispersion on the surface of polymer materials. The resulting HCP-DPPF exhibited remarkable catalytic activity and excellent durability for the Cr (VI) removal and reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in an aqueous solution. It could reach nearly 100% conversions within several minutes, even when the amount of the catalyst was used as low as 3 mg. Moreover, the HCP-DPPF can be reused 14 times and still retain high conversion efficiency over 92%. The results illustrate in situ immobilization of DPPF onto hyper-cross-linked polymers which improve the stability and electron transfer of the catalyst, while enhancing the activity of HCP-DPPF toward Cr (VI) removal and reduction of 4-NP.

Metal Catalysis with Knitting Aryl Polymers: Design, Catalytic Applications, and Future Trends

“…1,1′-Bis­(diphenylphosphino) ferrocene was also used to prepare an iron-containing knitting polymer, HCP-DPPF , which reached a specific surface area of 349.7 m 2 ·g –1 and was used as a heterogeneous catalyst in the reduction of 4-nitrophenol to 4-aminophenol . The catalyst showed an enhanced catalytic activity due to the synergic effect caused by the combination of aromatic rings and ferrocene units.…”

Low‐Cost Hypercrosslinked Polymers by Direct Knitting Strategy for Catalytic Applications

“…Direct knitting of 1,1′‐bis (diphenylphosphino)ferrocene with FDA is also successful, and the obtained HCP contains an iron center which can be used as a catalyst for the reduction of 4‐nitrophenol to 4‐aminophenol. [ 28 ]…”

Palladium Catalysts Supported in Microporous Phosphine Polymer Networks

“…Porous organic polymers, POPs, have showed high efficiency as heterogeneous catalysts due to properties such as high microporosity with tunable pore volume, high specific surface area, the possibility to incorporate high catalyst loadings or excellent thermal and chemical stability. In recent years, the inclusion of catalysts confined in very small pores has resulted in materials with excellent reaction yields, high turnover number (TON) and turnover frequency (TOF), high regioselectivities, high recyclability and low metallic contamination in the products obtained [1][2][3][4][5][6][7][8]. These POPs can be synthesized by multiple methodologies [9].…”

“…Lai's group has published the direct polymerization of [Pd(PPh 3 ) 4 ] and benzene [2]. Song's group has prepared materials by the knitting technique copolymerizing 1,1 -bis(diphenylphosphino)ferrocene and biphenyl, obtaining an efficient catalyst for the reduction of 4-nitrophenol, where the ferrocenyl units remain unchanged [3]. Recently, the preparation of polymers that maintain the molecular structure of the starting ruthenium or gold complexes with phosphine ligands and that behave as active catalysts in reactions of formic acid dehydrogenation [4], imination of alcohols [10], or hydration of alkynes [20] has been described.…”