Effects of Mn deposits from MMT on automotive catalysts in the absence and presence of other fuel additives. [Methylcyclopentadienyl manganese tricarbonyl (MMT)]

Conference · Mon Aug 01 04:00:00 EDT 1977 · Prepr., Div. Pet. Chem., Am. Chem. Soc.; (United States)

OSTI ID:6917054

Otto, K; Sulak, R J

The adverse influence of common additives and contaminants in fuel and engine oil, such as Pb, P, S and halides, on the removal of automotive emissions has been extensively demonstrated. Thus, the use of another fuel additive should be viewed with caution before it is widely accepted, and it has to be established that the undesired side effects on regulated emissions, i.e. hydrocarbons, CO and NO, or on the small amounts of unregulated emissions, such as NH/sub 3/, SO/sub 3/, H/sub 2/S and HCN, do not outweigh the potential benefits. For this reason, the effects of methylcyclopentadienyl manganese tricarbonyl (MMT) was studied, as this compound is already used in small amounts in several gasolines for the adjusting of octane rating. It appears that under the experimental conditions used, Mn derived from MMT, is converted in the combustion exclusively to Mn/sub 3/O/sub 4/. Recent analyses of deposits from engine systems also showed that this oxide was the end product in the oxidation of MMT. Although Mn/sub 2/O/sub 3/ is stable up to 940/sup 0/C, it loses oxygen above that temperature and the Mn/sub 3/O/sub 4/ produced does not revert to a higher oxide on cooling in air. Since Mn/sub 3/O/sub 4/ is very stable, it is, in retrospect, not surprising that this compound does not react with components of the catalyst. Deactivation, if any, would then appear to be limited to physical blockage of catalyst pores and channels. It should be mentioned, however, that some interaction may be possible if the catalyst contains silica. It has been claimed that silicates containing Mn can be formed on automotive catalysts under severe thermal stress. According to existing phase diagrams, such an event is unlikely under normal exhaust conditions.

• Research Organization: Ford Motor Co., Dearborn, MI
• OSTI ID: 6917054
• Conference Information: Journal Name: Prepr., Div. Pet. Chem., Am. Chem. Soc.; (United States) Journal Volume: 22:4
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330701* -- Emission Control-- Nitrogen Oxides
330702 -- Emission Control-- Carbon Monoxide
330703 -- Emission Control-- Sulfur Dioxide
330800 -- Emission Control-- Alternative Fuels
ADDITIVES
AIR POLLUTION CONTROL
AUTOMOBILES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYTIC CONVERTERS
CHALCOGENIDES
DEPOSITS
EQUIPMENT
EXHAUST GASES
FUELS
GASEOUS WASTES
GASOLINE
HYDROCARBONS
MANGANESE COMPOUNDS
MANGANESE OXIDES
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN OXIDES
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PETROLEUM PRODUCTS
POLLUTION CONTROL
POLLUTION CONTROL EQUIPMENT
TRANSITION ELEMENT COMPOUNDS
VEHICLES
WASTES