The tungsten heteropolyacid supported on activated bentonites as catalyst for selective oxidation of 2-propanol This article is dedicated to the memory of Prof. Željko Grbavčić, who recently passed away

Abstract

This paper provides the correlation between the catalytic activity and selectivity of catalysts with various loadings of heteropolyacids over bentonite in the vapour phase 2-propanol oxidation. The catalysts are characterised by energy dispersive spectroscopy, differential scanning calorimeter, ammonia temperature programmed desorption, infrared spectroscopy and a nitrogen adsorption/desorption method. Energy dispersive spectroscopy results have shown satisfactory agreement regarding chemical composition that corresponds to the desired content of heteropolyacids on bentonite. Thermal analysis confirmed the thermal stability of catalysts under the investigated region of oxidation reaction. NH3-TPD spectra demonstrated that all catalysts include two types of acidic sites: weak adsorption centres up to 390 K and a broad distribution of stronger acidic sites at higher temperatures. The catalysts were active in the vapour-phase conversion of 2-propanol to acetone in the temperature region of 343-553 K. An increase of HPW loading improves selectivity towards acetone formation.