摘要
为了准确测定多孔材料的比表面积,利用N2吸附法对多个具有0.5～40 nm不同孔径的样品进行孔结构分析,通过多点BET法计算样品的比表面积.结果表明：多点BET法的相对压力取值范围与样品的孔径密切相关;对于微孔样品,相对压力取值范围一般为0.01～0.1;对于孔径小于4 nm的介孔分子筛,相对压力取值范围应为0.05～0.2;对于孔径大于4 nm的介孔材料,相对压力取值范围一般为0.05～0.3;对于多级孔分子筛,应根据类型及孔结构特征确定相对压力取值范围.
To measure the specific surface area of pore materials, N2 adsorption method was applied to analyze the pore structure of samples with pore diameters from 0.5 to 40 nm. The specific surface areas of these samples were obtained by the multi-point BET method. The results show that the ranges of relative pressure are closely related to the pore diameter of samples by the multi-point BET method. The relative pressure is in the range of 0.01 to 0.1 for mieroporous materials. The relative pressure is in the range of 0.05 to 0,2 for mesoporous materials with the pore diameter less than 4 nm. The relative pressure is in the range of 0.05 to 0.3 for mesoporous materials with the pore diameter larger than 4 nm. For hierarchical molecular sieves, the relative pressure value range should be determined according to their types and pore structure characteristics.
出处
《中国粉体技术》
CAS
北大核心
2014年第4期68-73,共6页
China Powder Science and Technology
基金
国家自然科学基金项目
编号:21206017
关键词
多孔材料
多点BET法
比表面积
相对压力
孔结构
pore materials
multi-point BET method
specific surfacearea
relative pressure
pore structure
