Study On Modification Of Ni/BaTiO₃ Catalyst In CO₂ Reforming Of CH₄

In comparison to Al₂O₃, It is found that BaTiO₃ is a better support. Because ithas higher stability and no phase transformation in high temperature,and BaTiO₃supported Ni-base catalyst has stronger alkalinity, higher adsorption capacity of CO₂,higher resistance to carbon deposition, but Al₂O₃ showed greater specific surfacearea than BaTiO₃. Therefore, the serials of works about BaTiO₃-Al₂O₃ compositesupport catalyst were conducted in this dissertation. The effect of support onperformance of catalyst for CH₄/CO₂ reforming to syngas has been investigated, itwas found that Ni/BaTiO₃-Al₂O₃ catalyst showed higher catalytic activity thanNi/γ-Al₂O₃, Ni/BaTiO₃. Physico-chemical structure on catalysts surface has beencharacterized by some modem measurement techniques, such as TPD, H₂-TPR, BETand XRD. the result of XRD showed the formation of BaAl₂O₄ enhances the thermalstability of support significantly. The effect of Ni precursors on activity andreduction performance of catalyst in CO₂ reforming CH₄ has been investigated.Ni(NO₃)₂ as Ni precursors achieved more catalytic activity.The effects of MgO promoter on the physico-chemical and the catalyticperformance of Ni/BaTiO₃ catalysts for CH₄/CO₂ reforming to syngas were studiedby H₂-TPR, TPR_CO2, XRD, TPD and reaction activity evaluation, it was found thataddition of MgO Promoter increases the catalytic activity and resistance to carbondeposition of catalyst. Moreover, for the catalysts with proper amount of MgOpromoter, the dispersion of nickel was enhanced. However, excessive MgO promoterexerted a negative effect on the catalyst performance, as the content of MgOincreasing, the reactivity of catalysts is decreased. When the amount of MgO addedapproached 5.0%, the catalyst could display most suitable catalytic properties. Theeffect of preparation methods on catalytic activity of catalyst was also studied, andthe results showed that the catalytic activity of catalyst prepared by sol-gel washigher than that by the impregnation. It has more higher dispense degree and morespecific surface area. Catalyst prepared by sol-gel have desirable reduction and desorption properties. Furthermore, the result showed that different dipping orderscan affect the catalytic properties. The addition of MgO promoter improve alkalinityand resistance to carbon deposition of catalyst.