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

[Display omitted] •Direct activation of ethane & propane is thermodynamically favored at temperatures above 5000 °C.•Mo oxide supported on Sulfated hafnia (SH) solid acid catalyst is introduced to activate ethane & propane.•High selectively towards ethylene and propylene is demonstrated at 550-6000 °C.•Very little deactivation is observed, but there is measurable carbon deposition with time. 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.