Tin passivation of vanadium in metal-contaminated fluid-cracking catalysts: Electron paramagnetic resonance studies

Journal Article · Sat Mar 31 23:00:00 EST 1990 · Journal of Catalysis; (USA)

DOI:https://doi.org/10.1016/0021-9517(90)90291-Q· OSTI ID:6352389

Anderson, M W; Suib, S L ^[1]; Occelli, M L ^[2]

---

1. Univ. of Connecticut, Storrs (USA)
2. Unocal Corp., Brea, CA (USA)

Vanadium interactions with model fluid cracking catalysts and vanadium passivation with tin have been monitored by electron paramagnetic resonance (EPR). Model systems such as EuY, amorphous aluminosilicate gels, and EuY-gel mixtures have been investigated. Vanadium, introduced in the form of vanadyl naphthenate, is stabilized on the zeolite primarily as octahedrally coordinated VO{sup 2+} cations. In contrast, the gel preferentially sorbs vanadium where it is stabilized mainly in the form of V{sub 2}O{sub 5}. The presence of tin on the zeolite favors oxidation of VO{sup 2+} to V{sup 5+} and the generation of Sn-{sup 4+}O-V{sup 5+} species during steaming. Formation of europium orthovanadate (EuVO{sub 4}) is promoted by the presence of excess tin. Removal of Eu{sup 3+} ions from the zeolite lattice in the form of vanadates contributes to zeolite destabilization; thus excess tin is to be avoided.

• OSTI ID: 6352389
• Journal Information: Journal of Catalysis; (USA), Journal Name: Journal of Catalysis; (USA) Vol. 122:2; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400* -- Petroleum-- Processing
AGING
BIMETALS
CATALYST SUPPORTS
CATALYSTS
CATALYTIC CRACKING
CATALYTIC EFFECTS
CHALCOGENIDES
CHARGE STATES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
COLLOIDS
CRACKING
DECOMPOSITION
DISPERSIONS
ELECTRON SPIN RESONANCE
ELEMENTS
EUROPIUM
EUROPIUM COMPOUNDS
GELS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MAGNETIC RESONANCE
MATERIALS
METALS
MINERALS
OXIDES
OXYGEN COMPOUNDS
PYROLYSIS
RARE EARTH COMPOUNDS
RARE EARTHS
RESONANCE
STEAM
SURFACE PROPERTIES
SYNTHESIS
THERMOCHEMICAL PROCESSES
TIN
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
VANADATES
VANADIUM
VANADIUM COMPOUNDS
VANADIUM OXIDES
YTTRIUM
ZEOLITES