Secondary ketonization of primary alcohol over LaMn-based mixed oxides with perovskite-like structure

Abstract

LaMnO 3-based mixed oxides with perovskite-like structure both bulk and supported on La–Al 2O 3, show high catalytic activity in dehydrogenation of n-butanol to an aldehyde, which then undergoes a secondary reaction to produce a symmetrical ketone. Partial substitution of Cu, V or Sr into LaMnO 3 structure does not destroy the perovskite-like structure and enables to control the acid–base surface properties. It allows linking up these qualitative and quantitative features with activity and selectivity of these materials. The degree of n-butanol conversion depends on the total concentration of basic and acidic sites. Selectivity to butyraldehyde can be related with the share of basic sites. Selectivity to dipropyl ketone is affected both by the acidity and concentration of acidic sites. LaMnO 3/La–Al 2O 3 seems to posses an optimum set of surface characteristics for the examined ketonization of a primary alcohol.