Montmorillonite-supported Ni nanoparticles for efficient hydrogen production from ethanol steam reforming

Alkaline-promoted of NiAl-montmorillonite (NiAl-Mt) catalysts were prepared by ion-exchange method, tested in ethanol steam reforming (ESR) for hydrogen production, and characterized by a combination analysis of XRD, TPR, SEM, HR-TEM, EDS and N-2 adsorption-desorption. Characterization results indicated that the textural properties of the as-prepared catalysts are strongly dependent on the alkaline treatment. More importantly, a clear improvement on stability and catalytic activity, especially for the high selectivity to hydrogen, was observed in ESR. For NiAl-Mt/NaOH catalyst, similar to 74.7% selectivity of hydrogen was kept at 773 K during 10-h test, while that of NiAl-hydrotalcite (NiAl) catalyst decreased from 20.4% to 5.3% within 10 h, and the selectivity of hydrogen on NiAl-Mt was similar to 55.1%, accompanying with byproducts of acetaldehyde and ethylene. The improved activity and stability were attributed to the neutralization of acid sites by alkaline treatment, which accelerated the dehydrogenation and suppressed the dehydration of ethanol. (C) 2014 Elsevier Ltd. All rights reserved.