Effects of Yb₂O₃ promotor on the performance of Ni/SiC catalysts in CO₂ reforming of CH₄

Ni/SiC and Ni-Ybx/SiC (x=2%, 4%, 6%,10%) catalysts were prepared by the impregnation method, and the performances of catalysts in the carbon dioxide reforming of methane were studied in a fixed-bed reactor.The catalysts were characterized by BET, ICP-AES, XRD, H₂-TPR, TG-DTA, XPS and TEM techniques.The experimental results indicate that the appropriate addition amount of Yb is 4% to 6%.Ni-Yb4/SiC and Ni-Yb6/SiC catalysts exhibit excellent catalytic activity and stability at 800 ℃, and the conversion of CH₄ and CO₂ can be maintained over 90% during the 100 h testing. Yb₂O₃ promotor can inhibit the growth of nickel nanoparticles and reduce the amount of carbon deposition,therefore Ni-Yb/SiC catalysts show stable activity in the continuous reforming reaction.