The selective oxidation of glycerol over model Au/TiO2 catalysts — The influence of glycerol purity on conversion and product selectivity

•Au/TiO2 is a relatively active catalyst for pure glycerol oxidation.•Activity and selectivity change as crude glycerol is used.•The catalyst is poisoned by impurities in the crude substrate.•Ion-exchange and esterification of the crude substrate ameliorate this somewhat.

The activity and selectivity of a model Au/TiO2 catalyst was studied in the selective oxidation of glycerol as a function of the purity of the glycerol source. A reasonable conversion was noted when reagent grade starting materials were used. When crude glycerol from a FAME production facility was used, the activity of the catalyst was severely compromised and the selectivity of the reaction changed. Several low-cost approaches to purifying the crude glycerol were attempted but none resulted in the formation of a glycerol substrate whose conversion under reaction conditions matched that of the pure reagent grade substrate.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide