Pyrrole-Based Conjugated Microporous Polymers as Efficient Heterogeneous Catalysts for Knoevenagel Condensation

Abstract

Conjugated microporous polymers (CMPs) with robust architectures, facilely tunable pore sizes and large specific surface areas have emerged as an important class of porous materials due to their demonstrated prospects in various fields, e.g. gas storage/separation and heterogeneous catalysis. Herein, two new pyrrole-based CMPs with large specific surface areas and good stabilities were successfully prepared by one-step oxidative self-polycondensation of 1,2,4,5-tetra (pyrrol-2-ly)benzene or 1,3,5-tri (pyrrol-2-ly)benzene, respectively. Interestingly, both CMPs showed very high catalytic activity toward Knoevenagel condensation reaction, which was attributed to the inherent pore channels, high specific surface areas and abundant nitrogen sites within CMPs. Additionally, both CMPs displayed excellent recyclability with negligible degradation after 10 cycles. This work provides new possibilities into designing novel nitrogen-rich high-performance heterogeneous catalysts.

De Novo Design of a Pt Nanocatalyst on a Conjugated Microporous Polymer-Coated Honeycomb Carrier for Oxidation of Hydrogen Isotopes

“…The mesoporous structures of nitrogen-doped carbon improved the dispersion of Pt nanoparticles and endowed the material with a high electrocatalytic activity . Therefore, it is proposed that a reasonably designed support can enhance the interaction between Pt and the support and is an effective strategy to address the above challenges. , A conjugated microporous polymer (CMP) is a class of emerging material with a three-dimensional porous structure constructed by a variety of aromatic derivatives. , Taking advantage of its controllable porous, excellent chemical, and thermal stability, CMP-based catalysts exhibit fairly good catalytic activity for heterogeneous catalysis compared with Pt/C. − If the frameworks consist exclusively of nonpolar aromatic building blocks, CMP will exhibit high hydrophobicity . Moreover, owing to the rigid and fully aromatic networks, CMP possesses excellent resistance to radiation.…”

Cobalt Nanoparticle-Modified π-Conjugated Mesoporous Polymers for Electrocatalysis

“…The broad peak at 3440 cm −1 is attributed to the O−H peak, suggesting the presence of all requisite peaks (Figure S6). The powder X-ray diffraction (XRD) pattern displays the amorphous nature of the polymers, as depicted by a broad peak in the 2θ range of 15−28°, corresponding to a high π−π conjugated system 23 (Figure S7). The thermogravimetric analysis (TGA) shows that polymers are thermally stable up to 400 °C (Figure S8).…”

Porous organic polymers in solar cells

“…CMPs, albeit amorphous, win tremendous research attention due to their facile synthesis and adjustability. 23,73,74 For other classes of porous materials, either their stringent and inflexible synthetic conditions or the overall less crystalline feature with limited p-conjugation significantly hinders their optoelectronic applications. CTFs, for instance, bear outstanding merits due to the presence of a high amount of nitrogen, but their triazine ring synthesis drastically withholds their mass production and versatile applications.…”