Effect of the active phase-support interaction on the electronic, thermal and catalytic properties of [H–Pyr]+[HSO4]−/support (support = rice husk ash; corundum)

Abstract Influence of the surface active phase-support interaction on the electronic, thermal and catalytic performance of pyridinium hydrogen sulfate ([H–Pyr]+[HSO4, PHS]−) ionic liquid immobilized by a wetness impregnation method on rice husk ash (RHA) and corundum (Al-NA) carriers has been investigated in the current work. For that purpose, both the developed supports and the corresponding catalysts (PHS/Al-NA and PHS/RHA) were characterized in details by means of analytical methods such as N2 adsorption-desorption measurements, X-ray diffraction, X-ray photoelectron spectroscopy, spectroscopy in the ultraviolet and visible regions, infrared spectroscopy and thermogravimetric analysis. To compare the catalytic activity of PHS/Al-NA and PHS/RHA, a process of butyl acetate synthesis was applied as a test reaction. The physicochemical characterization revealed that the active phase-support interaction in the case of PHS/RHA catalyst is stronger than that between PHS phase and Al-NA. Based on this, the catalytic performance of PHS/RHA sample (expressed by substrate conversion degree) in the reaction of acetic acid esterification with butanol was found to be more pronounced with respect to that of Al-NA supported pyridinium hydrogen sulfate.