Synthesis of a palladium acetylide-based tubular microporous polymer monolith via a self-template approach: a potential precursor of supported palladium nanoparticles for heterogeneous catalysis

Abstract

A monolithic, palladium acetylide-based conjugated microporous polymer, Pd-CMP, was synthesized from a palladium dichloride and a trialkyne. The polymerization proceeded in two different ways, the dehydrohalogenation reaction between the alkyne and the palladium halide and the homocoupling reaction of the alkyne. Pd-CMP had a rigid hollow tubular structure. The in situ formed crystalline triethylammonium chloride (TEACl) rod played a critical role in the formation of the tubular morphology as a template. Through the attachment of the polymer particles to the surface of the rod and their reactions with soluble alkynes, a core-shell structure with a TEACl core and a polymer shell formed. The TEACl core was removed by washing with methanol to yield a hollow polymer tube. Pd-CMP showed a hierarchical pore structure and reversible compressibility. Supported Pd nanoparticles were prepared by one-step thermolysis of Pd-CMP as a heterogeneous catalyst. The average diameters of NPs in the products thermolyzed at 300 (Pd-CMP 300 ) and 500 C (Pd-CMP 500 ) were 2.6 and 4.1 nm, respectively.Pd-CMP 300 was used in the heterogeneous catalysis of the 4-nitrophenol reduction reaction and Suzuki-Miyaura coupling between iodobenzene and phenylboronic acid. The reaction yields were higher than 95%. The catalyst could be used for a flow reaction and easily recycled without significant activity loss. ; Tel: +82 2 880 7190 † Electronic supplementary information (ESI) available: Porosity and characterization data of the polymers and the catalytic reaction results. See

Macroscale Conjugated Microporous Polymers: Controlling Versatile Functionalities Over Several Dimensions

“…Postmodification of the polymer with thiolyne chemistry followed by Ag uptake led to a catalytically active material for a hetero-cyclization reaction. Subsequently, Chang et al [163] synthesized a monolithic, palladium acetylide-based conjugated microporous polymer (Pd-CMP) by using triethylammonium chloride (TEACl) as the template. Since TEACl forms insoluble rod-like crystals, they were applied as hard templates in CMP polymerization growth followed by removal of them via pyrolysis at 300/500 °C.…”

Processable Conjugated Microporous Polymer Gels and Monoliths: Fundamentals and Versatile Applications

“…76 As typical catalysts, CMP gels and monoliths with adjustable pore shape and size greatly facilitate the transport of matrix and catalytic products. 87,88,102 Furthermore, compared with CMP powders, CMP gels and monoliths have better recyclability and portability, improving their application value in the field of flame retardant, gas adsorption, and sensing.…”

“…In this regard, the introduction of noble metal catalytic sites into CMP monoliths through a polymerization reaction eliminates the noble metal loading process and produces stable chemical anchoring. 102 Due to the anchoring effect provided by the coordination groups of the CMP monolith and the confining effect provided by the micropores of the CMP monolith, fine and uniformly dispersed noble metal catalytic active sites are formed in molecular networks of the CMP monolith. The catalyst showed good activity in the low-temperature catalytic 4-NP reduction reaction and could keep the catalytic activity stable in a continuous flow state.…”

“…As an illustration of this, some CMP gels are conjugated with components with specific biological functions to form hydrogel networks, which can effectively control their degradation rate and immune irritation in vivo. , Meanwhile, a CMP-based hydrogel nanofiber membrane synthesized by electrospinning can selectively kill pathogens under visible light while providing sustained protection to the wound . As typical catalysts, CMP gels and monoliths with adjustable pore shape and size greatly facilitate the transport of matrix and catalytic products. ,, Furthermore, compared with CMP powders, CMP gels and monoliths have better recyclability and portability, improving their application value in the field of flame retardant, gas adsorption, and sensing.…”

The use of amino-based functional molecules for the controllable synthesis of noble-metal nanocrystals: a minireview

“…129,132,133 Compared with other methods, the templateassisted method has unique advantages for the synthesis of 3D noble-metal nanocrystals. [134][135][136][137] The construction of 3D nanostructures, such as porous and hollow nanostructures, could be carried out with the assistance of molecular templates, such as amphiphilic surfactants. 138,139 Amino-based groups are typical hydrophilic groups that could act well as amphiphilic surfactants for the synthesis of hollow and porous structures.…”