Characterization and performance of platinum-iridium reforming catalysts

Journal Article · Sat Sep 01 04:00:00 EDT 1979 · J. Catal.; (United States)

DOI:https://doi.org/10.1016/S0021-9517(79)80026-3· OSTI ID:6415356

Rasser, J C; Beindorff, W H; Scholten, J J.F.

Unsupported and ..gamma..-alumina-supported catalysts containing 0:1 to 64:1 iridium-platinum ratios were prepared and characterized by X-ray diffraction, Auger spectroscopy, and activity and selectivity tests for hexane and heptane reforming at 650/sup 0/K and 1 bar. Only monophasic solid solutions were observed. The surface concentration of iridium was low even at high bulk concentrations. The main effect of the iridium was suppression of the formation of carbonaceous deposits, possible by migration of deposited carbon atoms from platinum to iridium centers and their hydrogenation to methane. Under the mild reforming conditions used, no significant change in selectivity was observed with increasing iridium content, but at the higher pressures of industrial reforming when greater amounts of carbon deposit, the presence or iridium causes the known improvement of isomerization activity. Tests with acidic ..gamma..-alumina and with iridium/platinum on nonacidic ..cap alpha..-alumina confirmed the bifunctional character of the reforming catalysis, in which the alkane is dehydrogenated on a metal site, isomerized on an acidic site, and finally hydrogenated on a metal site.

• Research Organization: Delft Tech. Univ.
• OSTI ID: 6415356
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 59:2; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020500* -- Petroleum-- Products & By-Products
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
ALKANES
CARBONACEOUS MATERIALS
CATALYSTS
CATALYTIC EFFECTS
CATALYTIC REFORMING
CHEMICAL REACTIONS
DATA
DEPOSITS
ELEMENTS
EXPERIMENTAL DATA
HEPTANE
HEXANE
HYDROCARBONS
INFORMATION
IRIDIUM
MATERIALS
METALS
NUMERICAL DATA
ORGANIC COMPOUNDS
PERFORMANCE
PLATINUM
PLATINUM METALS
QUANTITY RATIO
REFORMER PROCESSES
STRUCTURAL CHEMICAL ANALYSIS
TRANSITION ELEMENTS