Coke-resistant lanthana promoted Ni/CeO₂-ZrO₂ catalysts for hydrogen generation via ethanol steam reforming

Ethanol steam reforming (ESR) has been a reliable and efficient process of renewable hydrogen generation. A highly stable and coke-resistant reforming catalyst was developed using La₂O₃ modified Ni catalyst supported on CeO_2-ZrO₂. A range of promoted (Ni-La/CeO_2-ZrO₂) and unpromoted (Ni/CeO_2-ZrO₂) catalysts were prepared in a laboratory and tested in a tubular fixed-bed reactor. Detailed characterizations of the fresh and spent catalyst revealed that the La₂O₃ promotion helped to tune the Ni dispersion, catalyst reducibility, and oxygen storage capacity of the catalyst. These properties account for the reforming activity of the catalysts and are reflected in enhanced ethanol (EtOH) conversion, H₂ yield, and catalyst stability. The coke-resistance property of La₂O₃ enhanced the catalyst stability and activity. 7.5Ni-7.5La/CeO_2-ZrO₂ catalyst showed an optimum H₂ selectivity (65 %) and EtOH conversion (97 %) at 600 °C, 1atm, S/C molar ratio 4.5:1 and WHSV_EtOH- 2.48 g/h-gcat.