The effect of Re, S, and Cl on the deactivation of Pt/. gamma. -Al sub 2 O sub 3 reforming catalysts

Journal Article · Sun Jan 01 04:00:00 EST 1989 · Journal of Catalysis; (USA)

DOI:https://doi.org/10.1016/0021-9517(89)90020-1· OSTI ID:6843808

Augustine, S M; Alameddin, G N; Sachtler, W M.H. ^[1]

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1. Northwestern Univ., Evanston, IL (USA)

The effects upon n-hexane (nC{sub 6}) conversion and catalyst deactivation caused by adding Re, S, and Cl to Pt/Al{sub 2}O{sub 3}, and also by varying the Pt and Re interaction, were studied. The nC{sub 6} reaction was studied at atmospheric pressure, 400 C, and H{sub 2}/nC{sub 6} = 9. The amount of carbon and hydrogen deposited on the catalyst during reaction was determined by temperature-programmed oxidation with an on-line mass spectrometer. Re addition to Pt/Al{sub 2}O{sub 3} increases the rate of deactivation, but lowers the amount of C retained on the catalyst. S addition increases activity maintenance, in addition to lowering the amount of C. Most remarkably, the H/C ratio of the carbonaceous layer is much higher for presulfided samples. Cl{sup {minus}} increases the amount on the support relative to that on the metal. The results are consistent with a model assuming that S is preferential chemisorbed on Re sites in bimetallic PtRe particles. This S divides the PtRe surface into small Pt ensembles. Consequently, hydrogenolysis activity is suppressed, and reorganization of carbonaceous overlayers into pseudo-graphitic entities that are detrimental to catalytic activity is impeded.

• OSTI ID: 6843808
• Journal Information: Journal of Catalysis; (USA), Journal Name: Journal of Catalysis; (USA) Vol. 115:1; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400* -- Petroleum-- Processing
ADDITIVES
ALKANES
ATMOSPHERIC PRESSURE
BIMETALS
CARBON
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CATALYTIC REFORMING
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISORPTION
CHLORIDES
CHLORINE COMPOUNDS
CONTROL
DEACTIVATION
DEHYDROGENATION
DEPOSITION
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
HEXANE
HYDROCARBONS
HYDROGEN
KINETICS
MASS SPECTROSCOPY
METALS
NONMETALS
ORGANIC COMPOUNDS
OXIDATION
PLATINUM
PLATINUM METALS
QUANTITY RATIO
REACTION KINETICS
REFORMER PROCESSES
RHENIUM
SEPARATION PROCESSES
SORPTION
SPECTROSCOPY
SULFUR
TEMPERATURE CONTROL
TRANSITION ELEMENTS