Preparation And Gas Adsorption Properties Of Carbon-based Porous Materials

With the acceleration of industrialization,industrial pollution has become a major global problem.Air pollution is a major challenge that has become more and more urgent to be solved in recent years.Therefore,accelerating the treatment of air pollution has attracted the attention of researchers around the world.Due to its unique internal structure and excellent properties,porous materials have become a highly promising adsorbent.Among many porous materials,porous carbon materials have outstanding advantages due to their relatively high specific surface area,low cost,and harmless to the environment.It plays an important role in many fields and it is an adsorbent material with commercial potential.In this work,a novel organic polymer gel precursor was prepared by sol-gel method using organic monomer.Then,a series of porous carbon materials with high specific surface area and abundant pore structure were prepared by physical or chemical activation,and the porous materials were applied to gas adsorption of inorganic substances and organic substances.1)A novel polymer precursor was obtained by sol-gel polymerization using pyrrole and formaldehyde,in this reaction pyrrole was used as nitrogen source and hydrochloric acid was used as catalyst.Then the porous carbon materials（PF-KOH-T or PF-CO₂-T,T stands for activation temperature）with high specific surface area(680-2340 m² g^-1),high nitrogen atom doping amount（relative atomic content from 2.9 to 11.4%）,and abundant pore structure were prepared by one-step potassium hydroxide activation or carbon dioxide activation.The as-prepared nitrogen-doped porous carbons as gas adsorbents display high carbon dioxide uptake capacities of 3.80–5.81 mmol g^–1 at 273 and 1.0 bar with excellent cycle stability.They also show excellent carbon dioxide adsorption capacities(2.40–3.37 mmol g^–1 at 1.0 bar)and good gas selectivities（CO₂/N₂ selectivities of 16.9–70.2）at 298 K.2)Polymer precursor was obtained by sol-gel polymerization using pyrrole and pyridoxal 5’-phosphate as raw material.Nitrogen-doped porous carbon materials NPCM-T（T stands for activation temperature）with a specific surface area of 1250-2520 m² g^-1 and a large number of microporous structures were fabricated via one-step carbon dioxide activation.The newly produced porous carbon possesses excellent adsorption performance to a variety of volatile organic compounds（VOCs）,the optimum adsorption capacities for toluene,benzene and methanol of NPCM-950 are as high as 16、20、44 mmol g^-1（148、154、140 wt%）.In addition,this data is a relatively high adsorption amount reported in the current literature and has broad application prospects.In addition,the resultant samples were tested for CO₂ adsorption at different temperatures.The adsorption capacities were3.57 and 2.32 mmol g^-1 at 273 and 298 K and 1.0 bar,respectively,indicating porous carbon materials with microporous structure and high specific surface area have broad application prospects in gas adsorption.