Acidity studies of fluid catalytic cracking catalysts by microcalorimetry and infrared spectroscopy

Journal Article · Sat Aug 01 04:00:00 EDT 1992 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1016/0021-9517(92)90070-X· OSTI ID:7252989

Chen, D; Sharma, S; Dumesic, J A ^[1]; Martinez, N Cardona; Bell, V A; Hodge, G D; Madon, R J ^[2]

---

1. Univ. of Wisconsin, Madison (United States)
2. Engelhard Corp., Iselin, NJ (United States)

The acidic properties of a USY-based fluid catalytic cracking catalyst steamed at various severities and amorphous silica-alumina were investigated by microcalorimetry and infrared spectroscopy using pyridine adsorption at 473 K. Microcalorimetric measurements of the differential heat of pyridine adsorption versus adsorbate coverage revealed a heterogeneous acid site distribution for the catalysts. Besides showing the expected progressive decrease in the number of acid sites for pyridine adsorption, measurements showed that the strength of Broensted acid sites decreased with increasing severity of steam treatment. Infrared spectra of adsorbed pyridine revealed a significant decrease in the ratio of Broensted to Lewis acid sites upon steaming. Amorphous silica-alumina had a relatively large number of acid sites of which a large proportion were Broensted acid sites. However, the strength of these Broensted sites was lower than that of the mildly steamed USY catalysts. This lower Broensted acid strength, the authors believe, is related to lower activity for gas-oil cracking over silica-alumina.

• OSTI ID: 7252989
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 136:2; 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
ABSORPTION SPECTROSCOPY
ADSORPTION
ADSORPTION HEAT
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
AMORPHOUS STATE
AZINES
BROENSTED ACIDS
CALORIMETRY
CATALYSTS
CATALYTIC CRACKING
CHALCOGENIDES
CHEMICAL REACTIONS
CRACKING
DECOMPOSITION
DISTILLATES
ELECTROMAGNETIC RADIATION
ENERGY SOURCES
ENTHALPY
FOSSIL FUELS
FUELS
GAS OILS
HEAT TREATMENTS
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
INFRARED RADIATION
INORGANIC ACIDS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
LEWIS ACIDS
MATERIALS
MINERALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PETROLEUM
PETROLEUM DISTILLATES
PETROLEUM FRACTIONS
PETROLEUM PRODUCTS
PH VALUE
PHYSICAL PROPERTIES
PYRIDINES
PYROLYSIS
RADIATIONS
SILICATE MINERALS
SILICON COMPOUNDS
SILICON OXIDES
SORPTION
SORPTIVE PROPERTIES
SPECTROSCOPY
STEAM
SURFACE PROPERTIES
THERMOCHEMICAL PROCESSES
THERMODYNAMIC PROPERTIES
ZEOLITES