Metal-support interaction in automotive exhaust catalysts: Rh-washcoat interaction

Journal Article · Fri Feb 01 00:00:00 EST 1980 · J. Catal.; (United States)

DOI:https://doi.org/10.1016/0021-9517(80)90406-6· OSTI ID:5410181

Yao, H C; Stepien, H K; Gandhi, H S

This work compares the effect of three washcoat materials, ..gamma..-Al/sub 2/O/sub 3/, ..cap alpha..-Al/sub 2/O/sub 3/, and ZrO/sub 2/, on the CO chemisorption capacity, thermostability, and catalytic activity for the H/sub 2/-NO reaction of Rh on a monolithic support. The Rh loading was analyzed by the conventional x-ray fluorescence method and by the inductive coupled plasma technique. The ZrO/sub 2/ and ..gamma..-Al/sub 2/O/sub 3/ washcoat show resistance to thermal deactivation. Since the BET area of ZrO/sub 2/ and ..gamma..-Al/sub 2/O/sub 3/ washcoats was five to seven times lower than that of ..gamma..-Al/sub 2/O/sub 3/ washcoat it was necessary to compare the chemical resistance of these catalysts for Pb, P, and S in fuel. Experiments were carried out in a pulse-flame reactor with isooctane fuel containing either 6 mg Pb/gallon (certification fuel) or 60 mg Pb/gallon with 0.8 mg P/gallon and 0.03 wt. % S. The results showed that using a fuel containing a ten times excess of lead over the certification fuel, the Rh/..cap alpha..-Al/sub 2/O/sub 3/ and Rh/ZrO/sub 2/ catalysts show significantly higher deactivation compared with a Rh/..gamma..-Al/sub 2/O/sub 3/ catalyst after 15,000 simulated miles of pulsator aging. These results indicate that the catalysts prepared on thermally stable waschcoats may be compatible only with fuels of low lead level (Pb < 6 mg/gallon). 1 figure, 2 tables. (DP)

• Research Organization: Ford Motor Co., Dearbon, MI
• OSTI ID: 5410181
• Journal Information: J. Catal.; (United States), Vol. 61:2
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
AUTOMOBILES
EXHAUST SYSTEMS
CATALYSTS
RHODIUM
CATALYTIC EFFECTS
ALUMINIUM OXIDES
CARBON MONOXIDE
CATALYSIS
CATALYST SUPPORTS
CHEMISORPTION
HYDROGEN
LEAD
NITROGEN OXIDES
PHOSPHORUS
SULFUR
X-RAY FLUORESCENCE ANALYSIS
ZIRCONIUM OXIDES
ALUMINIUM COMPOUNDS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
CRYOGENIC FLUIDS
ELEMENTS
FLUIDS
MECHANICAL STRUCTURES
METALS
NITROGEN COMPOUNDS
NONDESTRUCTIVE ANALYSIS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
REFRACTORY METALS
SEPARATION PROCESSES
SORPTION
SUPPORTS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
VEHICLES
X-RAY EMISSION ANALYSIS
ZIRCONIUM COMPOUNDS
330702* - Emission Control- Carbon Monoxide
400201 - Chemical &amp; Physicochemical Properties