聚苯并噁嗪基硫,氮共掺杂多孔炭的制备及其对CO_2的吸附性能（英文）

Synthesis of S,N co-doped porous carbons from polybenzoxazine for CO_2 capture

采用原位合成法,以对氰基苯酚、硫脲和甲醛为原料制备了聚苯并噁嗪基树脂,经炭化、活化得到相应的含硫,氮共掺杂的多孔炭。对样品的物理结构和表面化学性质进行了表征,结果表明活化后活性炭比表面积为1 512~2 385 m^2g^(-1),孔结构以微孔为主,且含有一定硫,氮元素。在1 bar和0、25℃条件下,未加造孔剂600℃活化样品的CO_2的吸附容量最高分别为6.96 mmol g^(-1)、4.55 mmol g^(-1),且具有一定的选择性和良好的循环稳定性。通过对CO_2吸附热及酸化实验分析,发现吸附过程同时存在物理吸附和化学吸附,且以有效的微孔结构物理吸附为主,硫/氮官能团的化学吸附为辅。

S,N co-doped porous carbons were synthesized from polybenzoxazine through solidification,carbonization and KOH activation using 4-cyanophenol,thiourea and formaldehyde as the monomers and a triblock copolymer(Pluronic F127)as a soft template.The samples were characterized by FT-IR,SEM,N 2 adsorption,elemental analysis and XPS.Results indicate that the activated samples had high surface areas of 1 511.6-2 385.1 m 2 g-1 with a large number of micropores and abundant sulfur and nitrogen functionalities.The templated samples had apparently lower contents of sulfur,nitrogen and oxygen than the un-templated ones due to the easy escape of volatile sulfur,nitrogen and oxygen compounds during carbonization and KOH activation.CO 2 uptake had contributions from both physical and chemical adsorption and depended on the volume of narrow micropores less than 0.8 nm and the numbers of basic sulfur and nitrogen functional groups.The un-templated sample activated at 600℃had the highest CO 2 uptakes of 6.96 and 4.55 mmol g-1 under 1 bar at 0 and 25℃,respectively,and was highly selective for CO 2/N 2 separation and had a high recyclable stability for CO 2 capture.