采用SEM和低温氮吸附方法研究了碳纳米管和活性炭的表面微观形貌及孔隙结构,通过固定床研究了炭材料SO_2吸附机理。研究结果表明:活性炭大孔直接暴露于表面,中孔和微孔分布于大孔内部,"聚合"是碳纳米管的重要特征;椰壳活性炭是微孔型吸附剂,煤基活性炭孔隙主要由微孔和大孔组成,碳纳米管氮吸附有明显的毛细凝聚现象,中孔和大孔是其孔隙主要组成;活性炭SO_2吸附过程受物理吸附控制,碳纳米管SO_2吸附不同于活性炭,同时受到物理吸附和化学吸附控制;孔径小于0.7 mm的微孔是炭材料SO_2吸附的主要场所。
SEM and nitrogen adsorption at 77.35 K were used to study micro-morphology and pore structure of carbon nanotubes and activated carbons.SO_2 adsorption characteristics of carbonaceous materials were studied with a fixed bed reactor.The results indicate that:macropores expose directly on the outer surface of activated carbon,mesopores and micropores open in interior of macropores for MJAC and YKAC.Aggregation is an important characteristic that differentiate CNTs from other carbonaceous adsorbents.YKAC is microporous adsorbent and MJAC shows both microporous and macroporus characteristics.Isotherms of CNTs behave capillary condensation phenomenon that indicates mesopores and macropores are the main pore structure.SO_2 adsorption on MJAC and YKAC is dominated by physical adsorption whereas SO_2 adsorption on CNTs is controlled by both physical adsorption and chemical adsorption.The micropores of 0.7 nm pore sizes are the dominant place for SO_2 adsorption.