单层分散阈值和负载型催化剂的阈值效应

Monolayer Dispersion Thresholds and Threshold Effect Displayed by Supported Catalysts

自发单层分散原理认为,许多负载型催化剂的活性组分可在载体表面自发分散。活性组分在载体表面的单层分散阈值可通过XRD相定量外推法等实验方法进行测定。通过单层分散阈值的测定可获取负载型催化剂表面结构、分散状态的有益信息,并为选择最佳的催化剂制备工艺条件提供依据。许多负载型催化剂活性组分的配比都可通过考察其单层分散阈值得以优化。负载型催化剂的许多物理化学性质突变值都与其单层分散阈值相联系,催化剂的阈值效应是明显的,阈值效应的提出为催化剂的研究提供了指导。

Principles of the spontaneous monolayer distribution holds that the active component of many supported catalysts will disperse spontaneously onto the surface of the cartier. The monolayer dispersion thresholds of the active component on the surface of the carrier can be measured by X-ray diffraction phase-quantitative extrapolation method, etc. By measuring the monolayer dispersion thresholds, the information of surface structure and dispersion of supported catalysts can be got, and the optimal preparative processing conditions of the catalysts can be elected. The proportioning of the active component of many supported catalysts can be optimized while its monolayer dispersion thresholds are observed. Mutation values of many physicochemical properties of supported catalysts are related to the monolayer dispersion thresholds, the threshold effect on catalysts is obvious, and the proposal of the threshold effect provides an instruction for the research of catalysts.