Conversion of ethanol into acetone is appealing because it could result in sustainable acetone production. Acetone is produced at a rate of over 10,000,000 tons per year. A variety of studies have been conducted on converting ethanol to acetone, and many of these studies involve catalysts that have reducible oxides (such as ZnZr solid solutions). Although there were a variety of studies, there was a lacking of molecular level mechanistic study. Most studies postulated that the C-C coupling occurs through aldol coupling. However, the community lacked clarification as to whether crotonaldehyde is an intermediate during acetone production or not. Additionally, the role of water promoting acetone production was not understood. We studied conversion of ethanol to acetone over La0.7Sr0.3MnO3–X.[1] We found that this catalyst is able to convert ethanol to acetone with unusually high selectivity. The 100 face is the most stable face and is able to produce acetone. Density functional theory calculations were used along with an innovative type of Steady State Transient Isotpic Kinetic Analysis (SSITKA) experiment to show evidence that a route for acetone formation that is 'directly' from aldol coupling exists, and is consistent with the data. The elementary step mechanism and study will be presented. One oxygen vacancy is involved in the mechanism, and this mechanism provides a plausible explanation for why the rate order for water is greater than first order. The water may be involved both in filling oxygen vacancies but also in shifting the equilibria of surface intermediates towards the acetone pathway.

Ethanol conversion to acetone: Elucidating the mechanism over La0.7Sr0.3MnO3–X , and a beyond re-oxidation explanation for the need to co-feed water over reducible oxides

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