Abstract |
Due to climate change, global warming, and the finite supply of energy supplies, environmental challenges have garnered a lot of academic and technological attention during the past few decades. The development of novel technologies based on cutting-edge materials for CO2 capture and conversion is necessary due to the escalating amounts of CO2 emissions that contribute to global warming. Porous organic polymers are ideal candidates for possible uses in CO2 collection and conversion because they have the necessary features, such as large surface areas, narrow pore size distribution, strong chemical and thermal stability, and functional groups. The synthesis of porous polymer networks based on porphyrin (TMP-net) and aluminum porphyrin (Al-TMP-net) moieties is described in this work. Tetra-methacrylate porphyrin cross-linker production was the key step in creating porous polymeric networks. In this work, First a porous porphyrin network (TMP-net) was prepared by free-radical polymerization of the tetra-methacrylate porphyrin derivative, employing azobisisobutyronitrile (AIBN) as the initiator. Next, the TMP-net was metalated by using dimethyl aluminum chloride, to create the aluminum porphyrin-based network (Al-TMP-net). Scanning electron microscopy (SEM) was used to characterize the networks' morphology after drying them in supercritical CO2 conditions, and Attenuated Total Reflection Fourier-transform infrared (ATR-FTIR), Energy-dispersive X-ray spectroscopy(EDS) , X-ray photoelectron spectroscopy (XPS), Ultra were used to confirm that the networks had successfully metallized. The BET surface area was measured by applying the Brunauer-Emmet-Teller (BET) method to the adsorption branch of the N2 isotherms of the polymers, with TMP-net having 622 m2g-1 while the Al-TMP-net showing lower BET surface area at 167 m2g-1. Additionally, at 273 K, the porous TMP-net absorbed more CO2 than the Al-TMP-net (1.54 mmol/g vs. 0.64 mmol/g, respectively). Also, both polymeric networks, TMP-net and Al-TMP-net were used as catalysts to study their catalytic performance in the presence of TBAB as co-catalyst, for the cycloaddition of CO2 in epichlorohydrin.. Proton nuclear magnetic resonance (1H-NMR) spectroscopy was used to ascertain the yield of the conversion of epichlorohydrin into the cyclic carbonate derivative. The results of the experiments revealed that Al-TMP-net had a high catalytic activity with a 93% conversion at 100°C, 1 atm, and 24 h of reaction time, whereas TMP-net performed similarly well with an 88% conversion during the same reaction. Finally, recycling experiments were conducted showing the stability of the catalysts after 5 runs.
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