Co/CeO2-ZrO2 catalysts prepared by impregnation and coprecipitation for ethanol steam reforming

Abstract

Co/CeO2-ZrO2 catalysts for the ethanol steam reforming were prepared by wet incipient impregnation and coprecipitation methods. These catalysts were characterized by nitrogen adsorption, TEM-EDX, XRD, H2-TPR, and CO chemisorption techniques. It was found that the catalyst reducibility was influenced by the preparation methods; catalysts with different reduction behaviors in the pre-reduction showed different catalytic activities toward hydrogen production. The H2-TPR studies suggested the presence of metal-support interactions in Co/CeO2-ZrO2 catalysts during their hydrogen pre-reduction, a necessary treatment process for catalysts activation. These interactions were influenced by the preparation methods, and the impregnation method is a favorable method to induce a proper metal-support effect that allows only partial reduction of the cobalt species and leads to a superior catalytic activity for the hydrogen production through ethanol steam reforming. At 450 °C, the impregnated catalyst gives a hydrogen production rate of 147.3 mmol/g-s at a WHSV of 6.3 h-1 (ethanol) and a steam-to-carbon ratio of 6.5.