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负载催化剂的金属分散度测定,有化学吸附法和物理方法。化学吸附法是基于某些气体如H_2、O_2、CO等能选择性地化学吸附在金属表面上,而且吸附分子与金属表面原子之间存在一定的化学计量关系。因此,通过测定这些气体在金属表面上的化学吸附量,就能计算出金属的分散度。虽然化学吸附法需要预先确定或假设化学吸附的计量关系式,但对于高度分散的负载金属,由于它的晶粒微小,有较高的测定灵敏度。尤其用气体色谱装置的化学吸附动态
Metal catalyst dispersion degree of determination, chemical adsorption and physical methods. Chemisorption is based on the selective chemisorption of certain gases such as H 2 O 2 and CO on metal surfaces, and there is a certain stoichiometric relationship between adsorbed molecules and metal surface atoms. Therefore, by measuring the amount of chemical adsorption of these gases on the metal surface, the degree of metal dispersion can be calculated. Although the chemical adsorption method requires a predetermined or assumed chemical adsorption relationship, it has a high sensitivity for highly dispersed supported metals due to its fine grain size. In particular, chemisorption kinetics with gas chromatography