Hydrogen production from decalin dehydrogenation over Pt-Ni/C bimetallic catalysts

Pt-Ni bimetallic catalysts and the corresponding monometallic Pt catalysts supported on active carbon were prepared by incipient wetness impregnation and characterized by X-ray diffraction, N₂ adsorption, and NH₃-temperature programmed desorption. Their activities for decalin dehydrogenation were investigated at a superheated liquid film state in a batch reactor. The effects of temperature, impregnation sequence, and Pt/Ni molar ratio on the dehydrogenation activity and the naphthalene yield were investigated. The results show that the Pt-Ni bimetallic catalyst significantly enhanced hydrogen evolution compared with either Ni or Pt monometallic catalyst. The highest dehydrogenation conversion and naphthalene yield were obtained when the Pt/Ni molar ratio was 1:1 and Pt was impregnated first. The experimental results were correlated with density functional theory calculations of hydrogen binding energy (HBE) on different catalytic surfaces. The correlation confirmed that bimetallic surfaces with stronger HBEs had higher dehydrogenation activities.