Some mechanistic correlations between impregnation and activation operations for the preparation of high-selectivity supported metal catalysts

From reaction-engineering analysis of catalyst performances, it is concluded that the essential structural requirements for the high-selectivity (i.e., demonstrative of 100% purity of catalytic function) supported metal catalysts, particularly, for the oxidation catalysts on silver and copper bases, comprise three classes of uniformity principles concerning the distribution, the size or the microsurface structure, and the microscopic environment of catalyst materials in structural matrices of the catalyst system, which are respectively related to (1) the porous support, (2) the dispersed metal particles or agglomerates, and (3) the situation of supporting the latter. According to these uniformity principles, the selection of suitable supports having the prerequisite uniform pore and surface structure and the correct impregnation and activation procedures for the preparation of high-sélectivity catalysts are discussed, and some demonstrative examples are illustrated together with interpretations of mechanistic correlations between the operations.