纳米级含钴介孔分子筛的合成与表征

SYNTHESIS AND CHARACTERISTICS OF COBALT-CONTAINING NANOSIZED MESOPOROUS MOLECULAR SIEVE

以硅酸钠、偏铝酸钠和氯化钴为原料,十六烷基三甲基溴化铵为模板剂,体积比为1:1的硫酸使pH=11,用两步水热法制备含钴介孔分子筛(CoMCM-41).用粉末X射线衍射、Fourier变换红外、程序升温还原、原子力显微镜、比表面和孔径测定等方法表征样品的物化性能.结果表明:合成的纳米CoMCM-41,经5 50 ℃焙烧可以有效去除模板剂并不影响孔结构.CoMCM-41的比表面积大于500 m2/g,孔径分布为3.5～4.0 nm,粒径分布为20～40 nm.因此,用两步水热法可以控制粒径并制备纳米级CoMCM-41.

A cobalt-containing mesoporous molecular sieve （CoMCM-41） was synthesized by the two-step hydrothermal method starting from sodium silicate, sodium meta-aluminates, and cobalt chlorate, using cetyhrimethyl ammonium bromide as a template, and adjusting thepH value of the reaction solution（equal to 11） by adding H2SO4 at a volume ratio of 1 ： 1. The synthesized CoMCM-41 was characterized by X-ray diffraction. Fourier transform infrared, nitrogen adsorption surface and porosity measurements, atomic force microscope, and temperature programmed reduction. The results show that nanosized mesoporous CoMCM - 41 has a specific surface area more than 500 m^2/g with pore sizes of 3.5-4.0 nm, and particle sizes of 20-40 nm. Calcination at 550℃ completely removes the template used and the pore structure is not affected. The two-step method can be used to synthesize nanosized cobalt-containing mesoporous molecular sieves CoMCM-41.