Solvent-free selective oxidation of primary alcohols-to-aldehydes and aldehydes-to-carboxylic acids by molecular oxygen over MgO-supported nano-gold catalyst

Magnesium oxide supported nano-gold catalyst (prepared by the homogeneous deposition precipitation technique) showed high activity/selectivity and excellent reusability in the oxidation of different primary alcohols and aldehydes to corresponding aldehydes and carboxylic acids, respectively, by molecular oxygen (under atmospheric pressure) in the absence of any solvent. Influence of the catalyst calcination temperature (400–900 °C), reaction temperature (50–120 °C) and use of different solvents (viz. toluene, p-xylene, DMF or DMSO) on the oxidation reaction has also been studied.

Graphical abstractLiquid phase oxidation by molecular O2 of different primary alcohols and aldehydes to corresponding aldehydes and carboxylic acids with high yields can be accomplished in the absence of any solvent using a reusable magnesium oxide supported nano-gold catalyst.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The Au/MgO catalyst shows very good performance in both processes. ► It shows very high activity under solvent-free conditions. ► It is easily separable and reusable in both the reactions. ► Both the oxidation protocols are green/environmentally friendly.