Mechanisms of product formation from the pyrolytic thermal degradation of catechol.
Catechol has been identified as one of the most abundant organic products in tobacco smoke and a major molecular precursor for semiquinone type radicals in the combustion of biomass material. The high-temperature gas-phase pyrolysis of catechol under hydrogen-rich and hydrogen-lean conditions was studied using a fused-silica tubular flow reactor coupled to an in-line GC/MS analytical system. Thermal degradation of catechol over temperature range of 250-1000 degrees C with a reaction time of 2.0s yielded a variety products including phenol, benzene, dibenzofuran, dibenzo-p-dioxin, phenylethyne, styrene, indene, anthracene, naphthalene, and biphenylene. Ortho-benzoquinone which is typically associated with the presence of semiquinone radicals was not observed and is proposed to be the result of fast decomposition reactions that lead to a variety of other reaction products. This is in contrast to the decomposition of hydroquinone that produced para-benzoquinone as the major product. A detailed mechanism of the degradation pathway of catechol is proposed.
Lomnicki
Slawomir
S
Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA.
Truong
Hieu
H
Dellinger
Barry
B
D001572:Benzofurans / Q000737:chemistry; D016227:Benzoquinones / Q000737:chemistry; D002396:Catechols / Q000737:chemistry*; D004147:Dioxins / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D006358:Hot Temperature
D001572:Benzofurans; D016227:Benzoquinones; D002396:Catechols; D004147:Dioxins; C025232:semiquinone radicals; C023614:dibenzofuran; C034221:catechol; C020887:dibenzo(1,4)dioxin