On the process for furfural and HMF oxidative esterification over Au/ZrO2

•Good results were obtained with the Au/ZrO2 catalyst without the use of a base.•Many variables (T, P, reaction time, and nature of the oxidant) were optimised.•O2 pressure can be lowered from 6 to 1 bar for both processes.•Data on the reaction mechanism were also verified by FTIR spectroscopy measurements.•The reaction proceeds through direct selective oxidation of furfural to the desired furoate.

The process for the oxidative esterification of furfural and HMF on Au/ZrO2 catalyst has been deeply investigated. Many variables, such as reaction time, temperature, pressure, and nature of the oxidant, have been optimised. For both processes, a considerable effect of the reaction temperature has been evidenced in the range here investigated (60–140 °C). As regards furfural, oxygen pressure can be lowered from 6 to 1 bar without significant changes in the catalytic performances. Molecular oxygen can be replaced by the more economic air, still at very low relative pressure (0.5 bar). In the case of HMF, oxygen pressure can be lowered from 6 to 1 bar without significant changes in the catalytic performances. Data on the reaction mechanism have been also verified by FTIR spectroscopy measurements taken in opportune experimental conditions in order to mimic reaction conditions.

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