A Comparative Study of Basic, Amphoteric, and Acidic Catalysts in the Oxidative Coupling of Methanol and Ethanol for Acrolein Production.

The impact of acid/base properties (determined by adsorption microcalorimetry) of various catalysts on the cross-aldolization of acetaldehyde and formaldehyde leading to acrolein was methodically studied in oxidizing conditions starting from a mixture of methanol and ethanol. The aldol condensation and further dehydration to acrolein were carried out on catalysts presenting various acid/base properties (MgO, Mg-Al oxides, Mg/SiO , NbP, and heteropolyanions on silica, HPA/SiO ). Thermodynamic calculations revealed that cross-aldolization is always favored compared with self-aldolization of acetaldehyde, which leads to crotonaldehyde formation.

Influence of Catalyst Acid/Base Properties in Acrolein Production by Oxidative Coupling of Ethanol and Methanol.

Oxidative coupling of methanol and ethanol represents a new route to produce acrolein. In this work, the overall reaction was decoupled in two steps, the oxidation and the aldolization, by using two consecutive reactors to investigate the role of the acid/base properties of silica-supported oxide catalysts. The oxidation of a mixture of methanol and ethanol to formaldehyde and acetaldehyde was performed over a FeMoO catalyst, and then the product mixture was transferred without intermediate separation to a second reactor, in which the aldol condensation and dehydration to acrolein were performed over the supported oxides.