Thermolysis on aluminum oxides chemisorbed 3-chlorophenol as example for the fly ash mediated surface catalysis reaction

The objective of this work is to acquire a better understanding of the gas-phase thermolysis of volatile chlorophenoxyaluminum compounds and to clarify the thermolysis on the fly ash chemisorbed chlorophenols. The purpose of this work was to elucidate the mechanism of the thermolysis of 3-chlorophenol chemisorbed on the surface of amorphous aluminum oxide or hydrated aluminum oxide. This is an example of the fly ash mediated surface catalysis reaction where 3,3′-dichlorodiphenylether and three derivates of dichloro-hydroxy-diphenyls are formed as the main thermolysic products. The proposed formation mechanism of 3,3′-dichlorodiphenylether and dichloro-hydroxy-diphenyls isomers is based on the dimerisation of the resonance stabilised 3-chlorophenoxy radical with the 3-chlorophenyl radical, which is formed by the expulsion of CO2 in the reaction of CO with the 3-chlorophenoxy radical. In this work some electronic and structural properties of aluminum-3-chlorophenolate intermediates are discussed. The results support and offer explanation for the previously suggested mass spectrometric fragmentation pathways and the mechanism of thermolysis. The influence of A1 atom as catalyst is explicitly provided for in the computational model.