Development of Pt-Ni bimetallic catalyst for oxidative reforming of methane with high resistance to hot spot formation

The catalyst bed temperature during the oxidative steam reforming of methane was investigated by an infrared thermography over γ-Al₂O₃ supported Pt-Ni bimetallic catalysts prepared by co-impregnation and sequential impregnation methods. It is clearly found that the catalyst bed temperature was strongly dependent on the way of impregnation, and sequentially introduced Pt had a great effect on the inhibition of hot spot formation. The highest temperature was lower than those over both monometallic catalysts of Ni and Pt. The profiles of TPR revealed that the addition of Pt promoted the reduction of Ni, and the structure of Ni during the sequential impregnation was different form that during the co-impregnation. FT-IR spectra of CO adsorption imply that Pt atoms added sequentially exist preferentially on the surface of metal particles. The surface enrichment of Pt is responsible for the effective overlap between the combustion and reforming zone to inhibit the hot spot formation.