Reproducible performance of a Ni/La2O3 aAl2O3 catalyst in ethanol steam reforming under reaction regeneration cycles
Abstract Equilibration of a Ni/La 2 O 3 aAl 2 O 3 catalyst has been studied with the aim of using it in ethanol steam reforming (ESR) under reaction regeneration cycles. The runs have been performed in a fluidized bed reactor, with the reaction steps being carried out at 500 degC and 700 degC, with a steam/ethanol (S/E) molar ratio of 6 and low values of space time (from 0.001 to 0.06 g catalyst h/g EtOH for which there is fast deactivation by coke formation. The catalyst is regenerated between steps in the reactor itself by coke combustion with air at 550 degC for 2 h. Reproducible performance of the catalyst in the successive reaction regeneration cycles requires a severe equilibration treatment consisting in a reaction regeneration cycle, with the reaction step at 700 degC. Several analytical techniques (XRD, H 2 chemisorption, TPR, and XPS) allowed proving that the catalyst undergoes partial Ni sintering in the equilibration treatment, which explains its lower activity compared to the non equilibrated catalyst.