Novel Oxidative Desulfurization of a Model Fuel with H2O2 Catalyzed by AlPMo12O40 under Phase Transfer Catalyst-Free Conditions

Abstract EN

A novel process was developed for oxidative desulfurization (ODS) in the absence of a phase transfer catalyst (PTC) using only Keggin heteropolyacids and their aluminum salts as catalysts.

Reactions were performed in biphasic mixtures of isooctane/acetonitrile, with dibenzothiophene (DBT) as a model sulfur compound and hydrogen peroxide as the oxidant.

Remarkably, only the AlPMo12O40-catalyzed reactions resulted in complete oxidation of DBT into DBT sulfone, which was totally extracted by acetonitrile, reducing the sulfur content of isooctane from the 1000 ppm to <1 ppm.

Ranking of catalyst efficiency is as follows: AlPMo12O40 > H3PMo12O40 > AlPW12O40 > H3PW12O40.

The absence of a PTC, acidic organic peroxides, and the use of hydrogen peroxide, an environmentally benign oxidant, make up the positive aspects of AlPMo12O40-catalyzed ODS reactions.

In these reactions, high rates of DBT removal (ca.

100%) were achieved within a short time (ca.

2 hours) and under mild reaction conditions.