Catalytic properties of well dispersed supported ruthenium alloys

Journal Article · Fri Mar 01 04:00:00 EST 1991 · Journal of Catalysis; (USA)

DOI:https://doi.org/10.1016/0021-9517(91)90083-G· OSTI ID:5556278

Coq, B; Bittar, A; Dutartre, R; Figueras, F ^[1]

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1. Lab. de Chimie Organique Physique et Cinetique Chimique Appliquees, Montpellier (France)

Small particles of Ru alloyed with Sn, Pb, Sb, Ge, or Si were prepared by reacting a well dispersed Ru/Al{sub 2}O{sub 3} parent sample with an organometallic compound of the desired modifier, by the so-called controlled surface reaction method. Two series of RuSn samples were thus obtained from parent Ru catalysts of 75% and 35% dispersion. The adsorption of hydrogen as a function of the amount of Sn shows a large initial decrease on the smaller particles, and a linear variation on the less dispersed catalyst. These catalysts were compared to Ru/Al{sub 2}O{sub 3} catalysts of widely varying dispersion in the hydrogenolysis of n-hexane (nH) and 2-methylpentane (2MP) at 458 K, and of 2,2,3,3-tetramethylbutane (TeMB) at 473 K. On pure Ru/Al{sub 2}O{sub 3} catalysts a strong effect of particle size is observed, both on turnover frequencies and on selectivities. When the dispersion is increased, turnover frequencies and deep hydrogenolysis decrease; the selectivity for TeMB hydrogenolysis is shifted from splitting of the central bond (2 iC{sub 4}) to demethylation (C{sub 1} + iC{sub 7}), and that of nH from the cleavage of external to internal bonds. The addition of about 0.3 wt% of Sn or Pb to the well dispersed Ru sample shifts the catalytic properties towards those of large particles, while a similar amount of Ge stimulates an opposite behavior and shifts the catalytic properties toward those of smaller particles. On larger Ru particles, the addition of Sn has only little effect on selectivity.

• OSTI ID: 5556278
• Journal Information: Journal of Catalysis; (USA), Journal Name: Journal of Catalysis; (USA) Vol. 128:1; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400 -- Petroleum-- Processing
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ADSORPTION
ALKANES
ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
ANTIMONY
BIMETALS
BUTANE
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DEHYDROGENATION
ELEMENTS
GERMANIUM
HEXANE
HYDROCARBONS
HYDROGEN
INTERMETALLIC COMPOUNDS
KINETICS
LEAD
METALS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PARTICLE SIZE
PENTANE
PLATINUM METALS
QUANTITY RATIO
REACTION KINETICS
RUTHENIUM
SEMIMETALS
SILICON
SIZE
SORPTION
SURFACE PROPERTIES
TIN
TRANSITION ELEMENTS