Rh-free three-way catalysts for automotive exhaust control

Book · Tue Jan 01 00:00:00 EST 1985

OSTI ID:5926472

Yokota, K; Muraki, H; Fujitani, Y

Platinum, palladium, and rhodium catalysts are evaluated on an engine dynamometer to examine the effects of air-fuel ratio (A/F), A/F amplitude and its frequency on the conversion efficiencies of NO/sub x/, THC and CO. Under steady-state conditions, Rh is more suitable for NO/sub x/ conversion than Pt and Pd. With increasing A/F amplitude, A/F for the maximum NO/subx conversion is shifted to rich side, while A/F for the maximum THC and CO conversions are shifted to the lean side. At the stoichiometric point, both Pt and Pd show the maximum conversions for particular frequency and their frequencies are shifted to higher values with increasing A/F amplitude. If the A/F amplitude and the frequency are selected to be optimum, Pt and Pd may be used as three-way catalysts (TWC). As a result of the durability testing until 50,000 km, Pd is promising as a main component of Rh-free TWC.

• OSTI ID: 5926472
• Report Number(s): TP-850129
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
54 ENVIRONMENTAL SCIENCES
CARBON MONOXIDE
AIR POLLUTION ABATEMENT
CATALYTIC CONVERTERS
PERFORMANCE TESTING
HYDROCARBONS
NITROGEN OXIDES
PALLADIUM
CATALYTIC EFFECTS
PLATINUM
RHODIUM
VEHICLES
AMPLITUDES
CATALYSTS
DYNAMOMETERS
FREQUENCY DEPENDENCE
FUEL-AIR RATIO
SERVICE LIFE
SILICON SOLAR CELLS
STOICHIOMETRY
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
DIRECT ENERGY CONVERTERS
ELEMENTS
EQUIPMENT
MEASURING INSTRUMENTS
METALS
NITROGEN COMPOUNDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PLATINUM METALS
POLLUTION ABATEMENT
POLLUTION CONTROL EQUIPMENT
SOLAR CELLS
SOLAR EQUIPMENT
TESTING
TRANSITION ELEMENTS
330701* - Emission Control- Nitrogen Oxides
330702 - Emission Control- Carbon Monoxide
330704 - Emission Control- Hydrocarbons
500200 - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)