Owing to their high physicochemical stability and low skeleton density, polymers are highly promising for capturing the greenhouse gas CO 2 . However, complicated monomers, expensive catalysts, and/or severe conditions are usually required for their synthesis, which makes the process costly, tedious, and hard to scale up. In this paper, a facile nucleophilic substitution reaction is developed to synthesize polymers from low-cost monomers, namely chloromethylbenzene and various diamines. Due to the appropriate reactivity of monomers, the polymerization takes place at a low temperature of about 60 °C in the absence of any catalysts. A series of polymers containing plentiful secondary amines are successfully fabricated; these secondary amines provide a proper adsorbate−adsorbent interaction from the viewpoints of selective capture of CO 2 and energy-efficient regeneration of adsorbents. Moreover, the materials possess well-defined micropores with the dimension close to the size of adsorbate molecules and subsequently, exhibit the molecule sieving effect. As a result, these materials are active in selective adsorption of CO 2 and show high CO 2 /N 2 and CO 2 /CH 4 selectivities. More importantly, the adsorbents can be completely regenerated under mild conditions, and no loss in activity is detected after eight cycles.
Selective reduction of supported CuO to Cu2O was realized using the strategy of vapor-induced reduction, in which HCHO/H2O vapor diffuses into the pores of the support and interacts with predispersed CuO. This new strategy allows the fabrication of supported cuprous sites at much lower temperatures within a short time, avoids the formation of Cu(0) with a Cu(I) yield of nearly 100%, and results in materials with good adsorption performance, which is impossible to achieve by conventional methods.
Porous polymer networks have great potential in various applications including carbon capture. However, complex monomers and/or expensive catalysts are commonly used for their synthesis, which makes the process complicated, costly, and hard to scale up. Herein, we develop a molecular template strategy to fabricate new porous polymer networks by a simple nucleophilic substitution reaction of two low-cost monomers (i.e., chloromethylbenzene and ethylene diamine). The polymerization reactions can take place under mild conditions in the absence of any catalysts. The resultant materials are interconnected with secondary amines and show well-defined micropores due to the structure-directing role of solvent molecules. These properties make our materials highly efficient for selective CO2 capture, and unusually high CO2/N2 and CO2/CH4 selectivities are obtained. Furthermore, the adsorbents can be completely regenerated under mild conditions. Our materials may provide promising candidates for selective capture of CO2 from mixtures such as flue gas and natural gas.
in Wiley Online Library (wileyonlinelibrary.com) N-doped porous carbons (NPCs) are highly promising for CO 2 capture, but their preparation is severely hindered by two factors, namely, the high cost of N-containing polymer precursors and the low yield of carbon products. Here we report for the first time the fabrication of NPCs through the rational choice of the polymer NUT-4, with low cost and high phenyl density, as precursor. For the material NPC-600 obtained from carbonization at 6008C, the yield is as high as 52.1%. The adsorption capacity of CO 2 on NPC-600 reaches 6.9 mmol/g at 273 K and 1 bar, which is obviously higher than that on the benchmarks, including 13X zeolite (4.1 mmol/g) and activated carbon (2.8 mmol/g), as well as most reported carbon materials. Our results also demonstrate that the present NPCs can be completely regenerated under mild conditions. The abundant microporosity and "CO 2 -philic" (N-doped) sites are responsible for the adsorption performance.
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