Tuning metal-support interaction and oxygen vacancies of ceria supported nickel catalysts by Tb doping for n-dodecane steam reforming

Catalytic steam reforming of long-chain hydrocarbons has drawn great attention for hydrogen production, which can be used for on-board/on-site fuel cell or hypersonic vehicle thermal protection. Herein, solid oxides of Tb-doped ceria support Ni with high activity and stability for steam reforming of n-dodecane have been developed using a citric-acid-assisted sol-gel method. High hydrogen production rate of 4800 µmol/min was achieved at 600 °C under water to carbon ratio of 2 and LHSV of 10 ml/gcat·h. The improved performance of n-dodecane steam reforming by Tb doping are ascribed to the moderate interaction between metal and support, highly dispersed of Ni, increased basicity sites and abundant surface oxygen vacancies. [Display omitted] •The Ni-Ce-Tb solid oxides fabricated by a simple citric-acid-assisted sol-gel method.•Achievement of efficient steam reforming of n-docecane with high conversion and low coke deposition at low temperature.•Moderate metal-support interaction and abundant oxygen vacancies co-affect the catalytic performance for n-dodecane steam reforming. Hydrogen is a green and efficient energy carrier that can be applied directly in fuel cell system. On-board/on-site hydrogen production for a portable fuel cell is urgently required, and catalytic steam reforming of liquid hydrocarbons is a promising pathway. In this context, Ni catalysts supported on various Tb-doped ceria were synthesized by a citric-acid-assisted sol-gel method. The textural and physicochemical properties of the fresh and spent catalysts were characterized by different techniques including XRD, N2 physical adsorption, H2-TPR, H2-TPD, TEM, SEM, XPS, EPR, TG and Raman. Catalytic performance of the as-prepared catalysts was evaluated in steam reforming of n-dodecane. The conversion of n-dodecane and hydrogen production rate were measured at LHSV of 10 ml/gcat·h and H2O/C = 2 and 4 in a fixed-bed tubular reactor. The reaction data showed that Tb dopant affected both the conversion of n-dodecane and the gas product composition. The origins of the improved performance by Tb doping were investigated, in which the moderate interaction between metal and support, highly dispersed Ni particles, increased basicity sites and abundant surface oxygen vacancies play key roles.