Study of a CeZrCoRh mixed oxide for hydrogen production by ethanol steam reforming

The catalytic activity of Ce2Zr1.5Co0.47Rh0.07O8−δ oxide has been studied in the reaction of ethanol steam reforming. The catalyst has been characterised by XRD, SEM, TEM–EDXS, IR operando, TPR and TPO techniques. The results show that there are three main causes of catalyst deactivation. The first one is the accumulation of carbonates species leading to the blocking of active sites. This phenomenon is partially reversible by high temperature treatment under inert gas flow. The second deactivation mechanism is the formation of carbonaceous deposits. It has been shown to be directly proportional to the quantity of ethanol converted during the ethanol steam reforming, and produced with a constant selectivity whatever the ethanol conversion level, it is irreversible by thermal cleaning. The third way of deactivation arises from a structural change of the catalyst under the reaction conditions, which gradually loses its redox capacity.

Research highlights► The formation of carbonaceous deposits is directly proportional to the quantity of ethanol reformed. ► The carbonaceous deposits are produced with a constant selectivity whatever the ethanol conversion level. ► The accumulation of carbonates species leads to the blocking of active sites changing the redox capacity of CeZrCoRh.