Kinetic and process study of ethanol steam reforming over Ni/Mg(Al)O catalysts: The initial steps

• Dehydrogenation and dehydration are the predominant reactions.
• CH3CHO and C2H4 are primary products and formed in parallel.
• H2O and C2H5OH compete for the same active sites.
• The apparent activation energy is 110 kJ/mol.

In this work, a 2 wt.% Ni/Mg(Al)O catalyst was subjected to kinetic studies for the ethanol steam reforming (ESR) reaction at 500 °C, with space-time ranging from 0.03 to 0.50 mg min/ml and with PC2H5OH:PH2O:PInert = 0.0163:0.0500:0.93 (atm) as standard conditions. The results indicate that dehydrogenation and dehydration of ethanol were the predominant reactions. CH3CHO and C2H4 were primary products and formed in parallel on different active sites. H2O and C2H5OH competed for the same active sites on the catalyst surface and the reaction order with respect to H2O was negative. The apparent activation energy for ethanol conversion was 110 kJ/mol. Furthermore, temperature-programmed desorption experiments confirmed the competing adsorption of C2H5OH and H2O. Temperature-programmed deuteration of used catalyst showed that the catalyst contained C2H4, CHx, acetate and carbonate species during ESR reaction.

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