Preparation of PtReAl2O3 catalysts by surface redox reactions II. Influence of the acid medium on Re deposition and PtRe interaction

✍ Scribed by C.L. Pieck; P. Marecot; J. Barbier

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 728 KB
• Volume: 141
• Category: Article
• ISSN: 0926-860X
• DOI: 10.1016/0926-860x(96)00052-x

✦ Synopsis

Bimetallic Pt-Re/A1203 catalysts are prepared under hydrogen atmosphere by a surface redox reaction between hydrogen adsorbed on a parent platinum/alumina catalyst and the perrhenate ion ReO 4. This reaction, called catalytic reduction, occurs only in an acidic medium, a maximum rhenium deposition appearing as a function of the concentration of the acid solution.

The preparation of bimetallic Pt-Re/AI203 catalysts by catalytic reduction of the rhenium salt on a highly dispersed platinum catalyst leads to bimetallic particles after activation by direct reduction under hydrogen. The calcination at 450°C partially destroys the interaction between the two metals, the effect being more obvious on chloride containing samples. The activation procedure produces the reverse effect at high rhenium loading deposited on a parent catalyst of low dispersion.