Effect of carbon on the reducibility of rhenium in Pt-Re/Al/sub 2/O/sub 3/ catalysts
The oxidation states of Re in three catalysts (0.4 wt% Pt + 0.6 wt% Re/Al/sub 2/O/sub 3/, 2.4 wt% Pt + 2.7 wt% Re/Al/sub 2/O/sub 3/, and 2.4 wt% Re/Al/sub 2/O/sub 3/) were evaluated with X-ray photoelectron spectroscopy (XPS). Reduction of the bimetallic catalysts with hydrogen at 500/sup 0/C and 1 atm gave predominantly Re(+4). Addition of small amounts of water to the hydrogen feed resulted in the reduction of the rhenium to Re(0) with complete chloride removal from the Pt-Re/Al/sub 2/O/sub 3/ samples. Reduction of the bimetallic catalysts in butane + hydrogen at 500/sup 0/C gave Re(0) without significant chloride removal. The 0.4 wt% Pt + 0.6 wt% Re/Al/sub 2/O/sub 3/ catalyst with Re in the +4 oxidation state also underwent reduction to give Re(0) in the presence of butane + hydrogen at 500/sup 0/C. In contrast, under identical conditions, the Re in the Re/Al/sub 2/O/sub 3/ catalyst was reduced to Re(+4), which indicates that Pt is necessary for the complete reduction of the Re with butane + hydrogen at 500/sup 0/C. These results suggest that rhenium is present predominantly as the zerovalent metal in the bimetallic reforming catalyst under reaction conditions.
- Research Organization:
- Univ. of Delaware, Newark (USA)
- OSTI ID:
- 5231248
- Journal Information:
- J. Catal.; (United States), Vol. 98:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CATALYSTS
CHEMICAL STATE
RHENIUM OXIDES
ALUMINIUM OXIDES
BIMETALS
BUTANE
CARBON
CATALYST SUPPORTS
CATALYTIC REFORMING
HYDROGEN
OXIDATION
PETROLEUM DISTILLATES
PHOTOELECTRON SPECTROSCOPY
PLATINUM
REDUCTION
STABILITY
X-RAY SPECTROSCOPY
ALKANES
ALUMINIUM COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
DISTILLATES
ELECTRON SPECTROSCOPY
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUELS
HYDROCARBONS
METALS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PETROLEUM
PETROLEUM FRACTIONS
PLATINUM METALS
REFORMER PROCESSES
REFRACTORY METAL COMPOUNDS
RHENIUM COMPOUNDS
SPECTROSCOPY
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
020400* - Petroleum- Processing