Study On The Preparation And Adsorption Properties Of Zr-based Getter

Getters are important for clean energy applications,gas purification and separation,carbon sequestration,vacuum field,MEMS(Micro-Electro-Mechanical Systems),semiconductor industry,and the recovery and utilization of nuclear reactor exhaust gas.Zr-based UIO-66 and Zr-based alloys have been used by many researchers to study the adsorption of gases such as CH₄,H₂O and CO.UIO-66,as an adsorbent material for H₂O removal,faces the problem of water absorption stability,which limits its application.However,ZrMnFe alloy getter has poor adsorption for CH₄gas when removing CH₄,CO,H₂O and other impurity gases.And commercial ST909(ZrMnFe Al)getter is expensive and difficult to obtain.Therefore,it is of great significance to study its substitute products or improve the existing getter materials for getter research.To solve the above problems,the adsorption properties of Zr-based MOFs(UIO-66)and ZrMnFe alloy getter were studied.UIO-66,UIO-66-NH₂,UIO-66-NO₂,UIO-66-(NH₂+NO₂)were successfully synthesized by introducing-NH₂and-NO₂functional groups into UIO-66.The samples were tested by XRD,SEM,IR,BET and water contact angle.The results show that the structure and morphology of the samples with the introduction of-NH₂and-NO₂functional groups do not change.Nitroterephthalic acid(BDC-NO₂)and amino terephthalic acid(BDC-NH₂)combine well in UIO-66 structure.After the introduction of functional groups,the specific surface area of the sample decreases,but the hydrophilicity increases.The water adsorption isotherm test of UIO-66,UIO-66-NH₂,UIO-66-NO₂and UIO-66-(NH₂+NO₂)samples shows that the water absorption capacity of UIO-66-NH₂-(NH₂+NO₂)is higher than that of UIO-66,UIO-66-NO₂and UIO-66-(NH₂+NO₂).The-NH₂functional group can improve the water absorption capacity of UIO-66.In this paper,Zr alloys are systematically studied from alloy preparation,microscopic characterization and macroscopic experiments combined with reaction bed theory.ZrMnFe alloy particles with particle size of 60?120 mesh and 120?200mesh were obtained by mechanical grinding.The ZrMnFe alloy particles were tested by XRD and ICP-OES test.The results show that the alloy exhibits C14 Laves phase structure.Using thermogravimetric experiments,the kinetic equation of CH₄decomposition reaction is=2430.5exp?-340.7/,which provides a theoretical basis for engineering practice.A micro ZrMnFe fixed bed reactor was designed to carry out penetration experiments on 1%CH₄gas,1%CO gas and mixed gas(0.5%CH₄+0.4%N₂+0.4%Ar+0.3%CO₂+0.2%CO+0.2%Ne+3%He+95%H₂).The experimental results show that when the temperature is 700?,the particle size of ZrMnFe is 60?120 mesh,and the gas flow rate is 20 ml/min,the adsorption performance of ZrMnFe getter for CH₄is the best,and it also has a good adsorption performance for CO.In the mixed gas penetration experiment,through the analysis of the penetration curve and the XRD and XPS analysis of the penetrated samples,it is found that N₂,CO and CO₂can nitride and oxidize the ZrMnFe getter,thus reducing the adsorption capacity of ZrMnFe getter for CH₄.