Modified niobia as a bifunctional catalyst for simultaneous dehydration and oxidation of glycerol

The niobia (Nb2O5) obtained in this study was modified by pretreatment with hydrogen peroxide to produce a bifunctional catalyst (Nb2O5//H2O2) with both acidic and oxidizing properties. The oxidizing properties of niobia were obtained by the generation of peroxo groups on the catalyst surface. The catalytic conversion of glycerin showed high activity using H2O2 as the oxidant. The catalytic tests monitored by mass spectrometry (ESI-MS) suggested the formation of ethers obtained by the condensation of glycerol (m/z = 167, 223, 240). Furthermore, it was observed that the modification of the catalyst directs the formation of larger molecules such as triglycerol compared to niobia without pretreatment with H2O2.

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► Synthetic niobia highly active was obtained by the generation of peroxo groups after treatment with H2O2.
► The mass spectrometry showed that ether was mainly produced.
► The catalytic activity of modified niobia was maintained for three reaction cycles.