Sorption-Enhanced Steam Reforming of Ethanol on a Novel K-Ni-Cu-Hydrotalcite Hybrid Material

Abstract

A multifunctional K-Ni-Cu hydrotalcite hybrid material was synthesized for hydrogen production via sorption-enhanced steam reforming of ethanol. The hydrotalcite material was used as support for the incorporation of nickel and copper, both used as active catalytic phases. This material was studied for its catalytic properties for steam reforming of ethanol; it was found that Cu preferentially catalyzes ethanol dehydrogenation and water gas shift reactions, while Ni is more suitable for acetaldehyde decomposition and steam reforming of methane. It was found that Ni and Cu formed a Ni0.5Cu0.3 alloy with the advantage of ensemble formation. Also, promising carbon dioxide adsorption capacity of the material was obtained. The potassium promoter together with the hydrotalcite material for carbon dioxide adsorption ensured a successful sorption-enhanced reaction process. High-purity hydrogen stream (99.8 mol % on dry basis) was obtained during the prebreakthrough period at 773 K with a water-to-ethanol molar ratio of 10 in the feed; the concentration of hydrogen then decreased to 67.1 mol % after the breakthrough period.