Preparation Of Rare Earth Metal Modified NiO Catalyst And Its Catalytic Purification Of N₂O Pollution

N₂O exists in the exhaust gas emission emitted by nitric acid,hekexic acid production plants and mobile,and fixed combustion sources.It is a polluted gas that can cause a strong greenhouse effect and a serious damage to the ozone layer.Effectively eliminating the N₂O emitted by industrial activities is of great significance to protect the atmospheric environment.To this end,researchers studied various N₂O purification methods at night,in which the direct catalytic breakdown technology has attracted much attention due to its simple operation and low energy consumption.However,in the process of three-step legal nitric acid,there is a relatively low temperature（below 800 K）.There is a polluting source gas（O₂,NO,H₂O）to inhibit the activity of catalysts.Mastering the basic mechanism and dynamic principles of N₂O formation is of great significance to minimize the pollution of N₂O.Therefore,it is crucial to develop catalysts that are cheaper,effective,and polluted with pollution-resistantnt sources.According to the above problems,we choose Ni O with good oxygen stability and high concentration of oxygen,and empty position as active components.The design and preparation of small sizes,certain marginal bits and structural defects,high catalytic activity and pollution source gas tolerance tolerance tolerance tolerance tolerance tolerance tolerance tolerance tolerance tolerance tolerance The rare earth composite nickel catalyst is a catalyst,and the relationship between the composition of the catalyst and the activity of the catalyst activity is discussed in detail.The specific content is as follows:1.Initially examined the decoration effect of NiO in the Rare earth element Sm,Nd,Dy,and Eu auxiliary agents in direct catalytic decomposition of the N₂O reaction.The active data of this series of catalysts shows that when the ratio of rare earth elements to Ni is 0.02,the Nd has the best role in modifying the Ni O catalyst.Conversion rate.In addition,through the preliminary structural tissue characteristics of the rare earth modification Ni O catalyst,it can be found that the doping of rare earth reduces the grain size of Ni O to varying degrees and increases the surface area of the catalyst.2.Based on the previous research,so as to figure out the poor water resistance in actual industrial applications,the Sm_0.06Ni with a good H₂O resistance performance was prepared by the common precipitation method.Studies have shown that the introduction of Sm in Sm_0.06Ni has the following functions:（1）Sm species（Sm₂O₃）on the surface of the Sm_0.06Ni catalyst,which not only reduces Ni O grain size but also generates a certain number of edge positions wrong and defects.（2）Sm₂O₃ weakens the Ni-O and increase the activity level.（3）During the reaction process,the oxidation and reduction cycle of Ni²⁺+Sm³⁺（?）Ni³⁺+Sm²⁺is formed on the Sm_0.06Ni surface.Based on the above changes,Sm_0.06Ni has better catalytic performance and lower activation energy than pure Ni O.On Sm_0.06Ni,the TOF at 350 ^oC was 4.1×10^-3 s^-1,which was 37 times that of pure Ni O.More importantly,Sm_0.06Ni shows excellent H₂O resistance performance under actual response conditions,and the N₂O conversion rate at 400 ^oC is about 76%.3.Detailed discussion of the promotion of Nd in NiO catalytic decomposition of Ni O catalysis.The results of the study show that the auxiliary Nd is highly scattered in the form of Nd₂O₃ in the Nd_xNi catalyst.Due to the blocking effect of Ni O’s microcrystalline growth due to a large radius of rare earth Nd,the addition of the additive Nd reduces the grain size of the active component Ni O in the catalyst,and increases the surface area of the catalyst.35.2 m²·g^-1 of Ni O catalyst dropped to 63.7m²·g^-1 of Nd_0.06Ni catalysts.In addition,the strong surface effect of the auxiliary Nd in the catalyst has largely weakened the Ni-O bond on the surface of the catalyst and improved the reaction rate of catalytic decomposition N₂O.The TOF value increased by 27 times on the basis of the pure Ni O catalyst.At the same time,the Nd_0.06Ni catalyst also shows excellent anti-NO_x performance.Even if 2 vol.%O₂and 100 ppmv NO are coexisting in the complex conditions of the reaction atmosphere,the conversion rate of N₂O at 350 ^oC can reach 72.5%.When NO,O₂,and H₂O exist in reaction gas components,the Nd_0.06Ni catalyst also shows excellent catalytic stability.