Mo oxide supported on sulfated hafnia: Novel solid acid catalyst for direct activation of ethane & propane

Abstract

Shale gas revolution has opened opportunities for conversion of light alkanes to value-added chemicals like ethylene and propylene. Literature suggests the use of bifunctional catalyst, consisting of a solid acid such as HZSM-5 and a metal oxide for direct conversion [7]. Here, we demonstrate a catalyst consisting of a novel Mo oxide-doped sulfated hafnia (SH) solid acid to convert ethane and propane.Mo-SH was synthesized via impregnation and characterized using BET, XPS, SEM-EDS, DRIFTS, NH3-TPD, XANES and TPO. Catalyst acidity was measured with NH3-TPD and DRIFTS. SEM-EDS and XPS were used to ensure the target loading of Mo on SH. XANES showed that Mo oxides are converted to Mo carbides with time, which are known as the active sites for dehydrogenation, the initial reaction step. Selectivity for ethane is 40–50 % to ethylene and for propane is 70–90 % to propylene at 550−600°C.No significant deactivation was observed for ∼16 h on stream.