Organolead antiknock agents—Their performance and mode of action

Catalytic inhibition of laminar flames by transition metal compounds

“…The alkyls of bismuth, lead, and thallium are anti-knocks, but those of mercury (which does not form particles) are not [38]. Richardson et al [39] showed that carboxylic acids increase the research octane number of TEL in engines, and argued that they reduced agglomeration of the PbO particles in the engine end-gas, but acknowledged that their arguments were qualitative. Zimpel and Graiff [40] used a fired engine to provide end-gas samples for transmission electron microscopy (TEM).…”

“…It is clear that halogens can release metals from solid oxides, and it may be possible to use this property to re-introduce the metals from the condensed oxide into the gas-phase where they can again inhibit the flame. Finally, the use of carboxylic acids as extenders of antiknock agents [39] (through the formation of metal salts which can persist in the gas phase) raises the possibility of such an approach for metal-based fire suppressants as well.…”