Novel highly dispersed Ni-based oxides catalysts for ethanol steam reforming

Abstract

To prepare high-performance Ethanol Steam Reforming (ESR) catalyst, copper and magnesium were added into NiAl Layered Double Hydroxides (NiAl-LDHs) employing the coprecipitation method as the second and third metals for reducing the sintering of nickel active components and controlling the acid sites. Afterward, NiCuMgAl-LDHs were wrapped on the SiO2 nanospheres to form a spherical layered structure. The results showed that, compared with the NiAl catalyst, after adding Cu metal, resulting from the synergistic effect of Ni–Cu, the ethanol conversion rate increased at different temperature ranges, and ethanol could be wholly converted at 500 °C. With the addition of Mg for neutralize the acid sites of the catalyst, no ethylene, ethanol dehydration product, was produced over the entire reaction temperature range (350–600 °C). NiCuMgAl-LDHs grows vertically on the surface of SiO2 because its hierarchical layered structure is beneficial to inhibit the collapse of laminates, which makes the active components of Ni on SiO2@NiCuMgAl more dispersed and exists edge and corner sites with few coordinative unsaturated active sites, thus exposing of active components and then enhanced performance. Finally, through the catalyst composition and structure optimization, the ethanol was converted entirely, and the stable hydrogen production was realized in the 19 h test.