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测定载体催化剂上金属颗粒大小的方法不少,但它们对同一样品的测定结果往往有些差异.我们曾指出叫用脉冲色谱氧吸附法测得的值为表面积体积平均粒径,X 射线粉末衍射线宽化法所得的为微晶的体积力矩平均粒径.由电子显微镜方法得到的统计值则可以同时求得各种不同定义的粒径.迄今为止,用电镜方法测定颗粒分布,一般采用透射电镜(TEM),而扫描电镜(SEM)测定方法还未见报道.本文提出用 SEM 来测定 Ag-SiO_2催化剂上银的粒子大小,并用对数正态分布法处理测得的数据.对数正态概率作图法早已用于处理一般颗粒的粒径分布,我们用它来处理载体上粒径为1000(?)左右的金属颗粒的扫描电镜测量数据.该法迅速、简便,结果较为满
There are a number of ways to determine the size of the metal particles on the supported catalyst, but they often differ somewhat in the determination of the same sample.We have pointed out that the value measured by pulse-oxygen adsorption is the surface area volume average particle size, the X-ray powder diffraction line Widening method for the crystallite obtained by the average volumetric diameter of the particle size obtained by statistical methods electron microscopy can be obtained at the same time a variety of different definitions of particle size so far measured by electron microscopy particle distribution, the general use of transmission electron microscopy (TEM), and the scanning electron microscopy (SEM) has not been reported yet.In this paper, the particle size of Ag on the Ag-SiO_2 catalyst was measured by SEM and the measured data were processed by logarithmic normal distribution method. Probabilistic mapping has long been used to process the particle size distribution of a typical particle, and we used it to process SEM measurements of metal particles with a particle size of about 1000 (?) On a support. This method is rapid and simple,