Comparative study on steam and oxidative steam reforming of ethanol over 2KCo/ZrO2 catalyst

•The addition of oxygen prevents carbon formation on 2KCo/ZrO2 catalyst.•The addition of oxygen causes the oxidation of cobalt phases of 2KCo/ZrO2 catalyst.•Selectivity to desired products over 2KCo/ZrO2 catalyst is lower in OSRE than SRE.•Temperature to achieve complete EtOH conversion over 2KCo/ZrO2 is lower in SRE.

The steam rreforming and oxidative steam reforming of ethanol were studied over 2KCo/ZrO2 catalyst which was prepared by support impregnation with cobalt nitrate-citric acid solution. The catalyst was characterized by N2 adsorption, H2 chemisorption, X-ray fluorescence, Raman spectroscopy, temperature-programmed reduction, temperature-programmed oxidation. The results indicate that the optimum EtOH/O2 molar ratio of 1/0.9 corresponds to the oxygen amount which prevents coke formation on the catalyst, when a constant molar ratio of H2O/EtOH = 9/1. However, the presence of oxygen causes oxidation of metallic particles which leads to oxidized cobalt active phases that behave poorly in the reformation reactions. Thus, compared to the SRE, both activity and selectivity to desired products over the 2KCo/ZrO2 catalyst in the OSRE process is definitely lower and the higher temperature for complete conversion of ethanol is required.

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