Ceria-promoted Ni-Co/Al2O3 Catalysts for n-dodecane Steam Reforming

Catalytic steam reforming of long-chain hydrocarbons has drawn great attention for hydrogen production or heat removement, which can be used for on-board/on-site fuel cell or hypersonic vehicle thermal protection. In this study, a series of Ni-Co bi-metal catalysts supported on Al2O3 with different ceria loadings have been prepared by a two-step impregnation method. Physical states and chemical properties of the as-synthesized catalysts have been characterized by XRD, nitrogen adsorption-desorption, H-2-TPR and TEM. Steam reforming of n-dodecane has been carried out to evaluate catalytic performance of the obtained catalysts at 700 A degrees C and atmospheric pressure in a fixed-bed tubular reactor. Both effects of CeO2 addition and Ni-Co alloying have been investigated to enhance catalytic activity and stability. After optimization, the catalyst promoted by 5 wt% ceria (NC/5CeAl) exhibits the highest conversion of n-dodecane (89 %) and the lowest coke deposition (reduced by 50 % compared with the one without ceria loading). The improvement in the performance of n-dodecane steam reforming is ascribed to the reduction of Ni particle size on alumina and the acceleration of coke gasification via redox, which has been achieved by Ni-Co alloying and CeO2 promotion. Ceria-promoted Ni-Co/Al2O3 catalysts have been developed and applied for n-dodecane steam reforming. The obtained results showed that ceria addition and Ni-Co alloying play an important role in n-dodecane steam reforming.