Kinetics and mechanism of the atmospheric oxidation of tertiary amyl methyl ether

Abstract

AbstractTertiary‐amyl methyl ether (TAME) is proposed for use as an additive to increase the oxygen content of gasoline as stipulated in the 1990 Clean Air Amendments. The present experiments have been performed to examine the kinetics and mechanisms of the atmospheric removal of TAME. The kinetics of the reaction of OH with TAME was examined by using a relative rate technique in which photolysis of methyl nitrite or nitrous acid was used as the source of OH. The OH rate constant for TAME and two major products (t‐amyl formate and methyl acetate) were measured and yields for ten products were determined as primary products from the reaction.Values determined for the rate constants for the reaction with OH were 5.48 × 10−12 (TAME), 1.75 × 10−12 (t‐amyl formate), and 3.85 × 10−13 cm3 molec−1 s−1 (methyl acetate) at 298 ± 2 K. The primary products (with corrected yields where required) from the OH + TAME that have been observed include (1) t‐amyl formate (0.366), methyl acetate (0.349), acetaldehyde (0.43, corrected), acetone (0.036), formaldehyde (0.549), t‐amyl alcohol (0.026), 3‐methyoxy‐3‐methyl‐butanal (0.044, corrected), t‐amyloxy methyl nitrate (0.029), 3‐methyoxy‐3‐methyl‐2‐butyl nitrate (0.010), and 2‐methoxy‐2‐methyl butyl nitrate (0.004). Mechanisms leading to these products involve OH abstraction from each of the four different hydrogen atoms of TAME. © 1995 John Wiley & Sons, Inc.