TRANSMISSION ELECTRON-MICROSCOPY, ENERGY-DISPERSIVE X-RAY SPECTROSCOPY, AND CHEMISORPTION STUDIES OF PT-GE GAMMA-AL2O3 REFORMING CATALYSTS/

A series of Pt-Ge/gamma-Al2O3 reforming catalysts have been prepared a nd studied by transmission electron microscopy (TEM), energy dispersiv e X-ray spectroscopy (EDX), and chemisorption. The catalyst performanc e in the reforming of octane was found to be dependent on the way in w hich the catalyst had been prepared, selectivity to aromatics being hi ghest when the catalyst had been prepared by a coimpregnation route. T he majority of the platinum was in the form of very small particles wh ich could not be seen by the microscope, whereas either all or the maj ority of the germanium was in the ionic state. PtGe, Pt3Ge2, and Pt3Ge particles were found, together with platinum, in the bimetallic catal ysts. Particle aggregation and alloy formation was observed for all th e catalysts after they had been used in octane reforming. (C) 1998 Aca demic Press.