Studies on the Formation and Structure of Highly Dispersed PdO Interacted with Br?nsted Acid Sites on Zeolite by EXAFS

The degree of the dispersion of PdO was highly dependent on the Al content of HZSM-5. This is due to the strong interaction between Br?nsted acid sites and PdO as demonstrated by the reversible transformation from aggregated metal Pd to highly dispersed PdO upon the successive reduction and oxidation treatments. The role of Br?nsted acid sites was considered to keep the dispersed state of PdO.