The Mode of Action of Tetraethyllead and Supplemental Antiknock Agents

Studies aimed at elucidating the mode of action of tetraethyllead and of supplemental antiknock agents have revealed the nature of the real antiknock species derived from TEL. The degradation products of TEL which are present in the exhaust of a motored engine support the theory that TEL functions as an antiknock by forming a “fog” of lead oxide particles in the end-gas zone. Moreover, the composition of the lead oxide particles appears to determine the relative antiknock effectiveness of TEL in a given fuel. Red lead monoxide particles with a distorted tetragonal crystal structure are indicated to be the most active antiknock degradation product of TEL.