Ethanol-gasoline fuel vehicles result in a statistically significant increase in emissions of ethanol, although they are environmentally friendly due to their lower levels of carbon oxide and hydrocarbon emissions. This work focused on catalytic oxidation of ethanol on octahedral molecular sieve (OMS-2) catalyst, which was synthesized using refluxing method. The catalyst demonstrated great reactivity with acetaldehyde as the major intermediate. Small amounts of formaldehyde were detected while little acetic acid was observed in the presence of oxygen. Results suggested that ethanol adsorption occurred through the breakage of O-H bond forming ethoxide species on Lewis acid sites of the catalyst and OMS-2 could partially oxidize adsorbed ethanol to acetaldehyde and formaldehyde from the consumption of catalyst lattice oxygen in the absence of oxygen flow. Acetaldehyde and formaldehyde formed were directly oxidized to carbon dioxide in the presence of an oxygen flow. The major path of ethanol complete oxidation on OMS-2 catalyst appeared to be the direct oxidation of acetaldehyde to carbon dioxide.

Volatile organic compounds (VOCs) emitted from many industrial processes and transportation activities are major organic pollutants in the atmosphere and toxic to human health. Octahedral molecular sieve (OMS-2) catalysts with different precursors and sulfate-acidified OMS-2 catalysts were synthesized using refluxing methods. The catalysts were investigated on complete oxidation of ethanol and acetaldehyde, and both demonstrated good reactivity. However, acidification resulted in a decrease in activity. OMS-2 catalyst using MnSO(4) as precursor exhibited the best catalytic performance and, thus, was selected for catalyst deactivation by sulfur dioxide. The results of this study suggested that the Mn-O bond of OMS-2 catalysts was the main determinant of the catalytic activity toward oxygenated VOC oxidation and weaker acid sites benefited higher acetaldehyde selectivity. Catalyst deactivation resulted from a strong but slow chemical interaction between the Mn-O bond and sulfur dioxide, probably forming manganese sulfate.

OMS-2 (2 9 2 type octahedral molecular sieve) and cerium doped OMS-2 were synthesized by refluxing method. The platinum doped on both samples was prepared by impregnation method for catalytic oxidation of formaldehyde. These catalysts were characterized by BET, XRD, SEM, H 2 -TPR and Laser Raman. Results show that OMS-2 formed needle-shape nanocrystal structure. The addition of Ce before the formation of the OMS-2 structure obstructs the process due to mismatch of the cation size. Rather than into the framework of the structure, the addition of Pt after the formation of the OMS-2 structure was loaded on the surface of catalysts, which strongly influenced the bonding of the Mn-O lattice of OMS-2. The properties of the catalyst structure determine the temperature of complete oxidation of HCHO while Pt promotes this reaction at a lower temperature range due to active surface oxygen species and lattice defects.

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