The Preparation Of La₂O₃ Modified Mcf And Nano-CeO₂ Loaded Nickel-based Catalysts And Their Catalytic Performance Research On CH₄-CO₂ Reforming Reaction

With the rapid progress of science and technology,energy has become very important in our society.But at the same time,environmental problems have become increasingly serious.As the vast consumption of coal,oil and other natural resources,the future of natural gas will gradually become the mainstream in the energy structure.On the other hand,the main cause of global warming is the production of the greenhouse effect and the greenhouse effect is mainly caused by carbon dioxide and methane,so reducing emissions of carbon dioxide and methane plays a positive role to the greenhouse effect.Carbon dioxide reforming of methane is of great importance because two greenhouse gases CO₂ and CH₄ can be directly transformed to the extremely useful synthesis gas.A traditional nickel-based catalyst was often employed to achieve this target because of the lower price.However,there still remained an intrinsic drawback of this kind of catalyst,that is,the catalytic activity of nickel-based catalyst is very low and the catalyst is subject to deactivation because of carbon deposition,so it is difficult to realize industrialization.In this paper,with MCF of the large BET as support and the alkaline oxide La₂O₃as promoter,we prepared several nickel-based catalysts with different lanthanum oxide content and nickel content.Experimental results showed that adding the La₂O₃can enhance the interaction between the support and the active metal,and also increase the dispersion of active metal.At the same time,the addition of lanthanum oxide can promote the adsorption and activation of carbon dioxide on support,and then restrain the carbon deposit to some extent.Therefore,the catalytic activity and stability of catalysts was improved obviously.In addition,nickel-based catalysts supported on metal oxide with TaskerⅢsurface,such as CeO₂（200）nanocube with TaskerⅢtype of strongly polar（200）surface as carrier were successfully prepared in this paper.The designed nanocube structure and the alternating ionic layers of CeO₂（200）surface can regulate the adsorption and activation of CO₂ and CH₄.Especially,it can prevent the deactivation resulted from the carbon depositing and sintering of nickel particles.Because of the special high surface activity,CeO₂ nanocube is beneficial to improve the dispersion of active metal,and can also increase the interaction between active metal and support,which can restrain the sintering of the nickel particles on the surface of catalyst,and also play a positive role to restrain the carbon deposit.The results showed that the activity of Ni-CeO₂（200）catalyst is superior to the Ni-CeO₂ normal catalyst with normal cerium dioxide as support and the Ni-CeO₂ cubic catalyst showed a better capacity of resistance to carbon deposition.