Performance of PtAl/sub 2/O/sub 3/ catalysts in automobile engine exhaust with oscillatory airfuel ratio

Journal Article · Fri Jan 01 04:00:00 EST 1988 · Ind. Eng. Chem. Res.; (United States)

DOI:https://doi.org/10.1021/ie00073a007· OSTI ID:5032477

Cho, B K

Performance of PtAl/sub 2/O/sub 3/ catalysts for the removal of CO, NO, and hydrocarbons in engine exhaust wass investigated using a fixed-bed reactor connected to a dynamometer-mounted engine. The effect of airfuel ratio oscillation on the catalyst performance was examined over a wide temperature range. Results showed good activity of fresh PtAl/sub 2/O/sub 3/ catalysts for the oxidation of CO and hydrocarbons as well as for the reduction of NO, when the feed composition oscillated symmetrically around a time-average stoichiometric point. Below the reaction lightoff temperatures, a feed composition oscillation at 0.1 Hz around a time-average stoichiometric point yielded higher conversions for all three pollutants than steady feed operation, whereas this trend reverses above the reaction lightoff temperatures. The presence of excess oxygen above the stoichiometric amount in engine exhaust lowered considerably the reaction lightoff temperatures for the oxidation of CO and hydrocarbons but severely suppressed the NO reduction activity of PtAl/sub 2/O/sub 3/ catalysts. The performance and reaction selectivity of the catalysts under engine exhaust conditions were further discussed in comparison with those under laboratory conditions in light of the chromatographic and antichromatographic effect occurring in the catalyst pellet.

• Research Organization: Physical Chemistry Dept., General Motors Research Labs., Warren, MI 48090-9055 (US)
• OSTI ID: 5032477
• Journal Information: Ind. Eng. Chem. Res.; (United States), Journal Name: Ind. Eng. Chem. Res.; (United States) Vol. 27:1; ISSN IECRE
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330701* -- Emission Control-- Nitrogen Oxides
330702 -- Emission Control-- Carbon Monoxide
330704 -- Emission Control-- Hydrocarbons
AIR POLLUTION ABATEMENT
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHROMATOGRAPHY
DESIGN
DYNAMOMETERS
ELEMENTS
ENGINES
EXHAUST GASES
FLUIDS
GASEOUS WASTES
GASES
HYDROCARBONS
KINETICS
MEASURING INSTRUMENTS
METALS
NITROGEN COMPOUNDS
NITROGEN OXIDES
NITROUS OXIDE
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PERFORMANCE TESTING
PLATINUM
PLATINUM METALS
POLLUTION ABATEMENT
REACTION KINETICS
SEPARATION PROCESSES
STOICHIOMETRY
TESTING
TRANSITION ELEMENTS
WASTES