METAL SUPPORT EFFECTS AND CATALYTIC PROPERTIES OF PLATINUM SUPPORTED ON ZINC ALUMINATE

Pt/ZnAl2O4 catalysts with platinum contents ranging from 0.1 to 1.17 wt.-% were characterized by temperature-programmed reduction, hydrogen chemisorption, high resolution transmission electron microscopy, electron energy loss spectroscopy and tested for isobutane dehydrogenation, using helium or hydrogen as reaction media. For low metal contents, the results suggest that platinum diffuses into the oxygen vacancies in the spinel lattice while at higher loadings, metal-metal interactions are dominant, leading to particle formation. The catalytic behaviour points to the necessity of strong Pt-H interactions to preserve activity.