Palladium nanoparticles supported on triazine functionalised mesoporous covalent organic polymers as efficient catalysts for Mizoroki–Heck cross coupling reaction

Abstract

A material based on palladium nanoparticles supported on nitrogen rich mesoporous covalent organic polymers exhibiting excellent catalytic activity towards Mizoroki–Heck cross coupling reaction.

Covalent triazine framework-supported palladium nanoparticles for catalytic hydrogenation of N-heterocycles

“…They found that the presence of triazine rings on the polymers is beneficial for enhancing the stability of Pd NPs. 45 Our recent results showed that Ru supported on CTF-1 could receive electron from N groups on CTF-1 as detected by 50 XPS. 48 Theoretical calculation also confirmed the electron donor states of N-doped CNTs.…”

“…The wilder diameter distribution of Pd 35 NPs on AC could be attributed to the irregular porous structure of AC and random anchoring sites. It was reported that the nitrogen substitution in cyclic hydrocarbons tunes the thermodynamic properties which is in 45 favor of reversible hydrogenation and dehydrogenation under mild conditions. 1, 4, 5 However, the difficulty of hydrogenation of N-heterocycle depends on the catalyst, solvent and functional group on the heterocycles.…”

“…In the literatures, similar shift can also be observed from supported 35 catalysts, indicating an electron transfer between support and catalyst. [42][43][44] Especially for the N modified carbon-based materials, nitrogen usually performs several tasks: (1) nitrogen sites, being electron donor, increase the electron density of metal particle; 44 (2) nitrogen sites provide the anchoring sites for metal 40 particles, leading to a good dispersion of catalyst; 30,45 (3) nitrogen sites could keep the metal in metallic state during air contact; 29,46 (4) metal on nitrogen sites may facilitate absorption reactant or desorption of products. 47 Pitchumani et al introduced nanosized Pd into mesoporous covalent organic polymer, 45 exhibiting excellent catalytic activity towards Mizoroki-Heck cross coupling reaction.…”

“…With high surface area, porosity and high amounts of nitrogen functionalities served as basic sites to anchor active metal 45 nanoparticles (NPs) of the covalent triazine frameworks (CTF) [19][20][21] newly developed by Thomas et al has the merits to meet the requirements mentioned above. There are a number of recent activities in applying CTF as catalyst supports in methane oxidation 22 and alcohols oxidation, 23,24 from which superior 50 performances over other carbon-based materials were observed which may be explained partially by the large amount of nitrogen functionalities and porosity in the frameworks, which can stabilize catalyst NPs from aggregation.…”

Covalent triazine polymers using a cyanuric chloride precursor via Friedel–Crafts reaction for CO2 adsorption/separation

“…Recently, POPs which can be constructed from light-weight elements linked by strong covalent bonds have attracted increasing attention for gas adsorption, storages and separation owing to their high stability against moisture, chemical stability with long lifetimes and easy handling [15]. These are known by their different product designations, such as Schiff base networks (SNWs) [16], benzimidazole-linked polymers (BILPs) [17], covalent triazine frameworks (CTFs) [18], polymers with intrinsic microporosity (PIMs) [19], porous aromatic frameworks (PAFs) [20], porous polymer frameworks (PPFs) [21], porous polymer networks (PPNs) [22], covalent organic frameworks (COFs) [23], element-organic frameworks (EOFs) [24], covalent organic polymers (COPs) [25], hypercrosslinked and conjugated microporous polymers (HCPs and CMPs) [26,27], covalent imine polymers (CIP) [28], and nitrogen-doped porous carbon materials (NPCs) [29]. The relatively low cost synthesis of this class of nitrogen chloride-catalyzed Friedel-Crafts reaction [33].…”