表面掺氮活性炭的制备及其甲醛吸附性能研究

Preparation of N-doped Activated Carbon and Effects of N-doping on Formaldehyde Adsorption

以苯胺（An）为氮源,在活性炭表面原位聚合、炭化制备掺氮活性炭,考察了苯胺添加量对活性炭的孔隙结构变化、表面含氮基团及甲醛平衡吸附量的影响.结果表明,活性炭与苯胺质量比10∶2条件下制备的掺氮活性炭（AC2）,其氮元素质量分数2.05％,总孔容和中孔容有所下降,而微孔率略有增加,这一变化有利于气相分子吸附.AC2的甲醛平衡吸附量379 mg/g,是市售气体净化用活性炭、竹炭的3～6倍,平衡吸附时间为6h.通过活性炭表面掺氮,增大孔隙周围电子云密度,增强对甲醛中羰基碳正离子的吸引力.由此提供了一条由商品活性炭改性制备甲醛去除用活性炭的有效途径.

Aniline （An） as nitrogen source, N-doped activated carbon was prepared by in-situ polymerization and carbonization. Effects of added aniline on pore structure, external nitrogen-containing groups and formaldehyde equilibrium adsorption capacity of the modified activated carbon （AC） were investigated. Results showed that N-doping activated carbon （ AC2 ） prepared by the mass ratio of mA,： mac with 10：2 had very high gas adsorption capacity. The sample AC2 has nitrogen content of 2.05%, and its total pore volume and mesoporous volume decrease, whereas microporous volume increases slightly. AC2 has gotten formaldehyde equilibrium adsorption capacity 379 mg/g, which is 3 -6 times high than commercial activated carbon and bamboo charcoal. Doping element N on the surface of activated carbon can increase the electron cloud density around the porosity and the attractiveness of carbonyl carbocation from formaldehyde. The present modification method is a promising convenient way to obtain the N-doped activated carbon with high removal capacity of formaldehyde.