Systhesis Of Mn-MOFs And Their Deuterogenic Oxides And The Study On Their Adsorbed And Catalized Properties

With the development of modern industry,the problem of air pollution is gradually getting people's attention.In recent years,the amount of typical pollutant CO and toluene shows obvious increasing trend in the air,the presence of these pollutants to a great extent affects people's health and living environment,so the elimination of CO and toluene is very meaningful.The waies of removal CO and toluene are including physical and chemical method.Physical method for removing CO has many disadvantages,therefore,eliminate the CO is not applicable.The characteristics of industrial organic waste is large gas volume and low concentration in this topic research,so toluene is suitable for the adsorption method.The catalytic reduction method of chemical methods only stay in the laboratory research stage,so when it needs to eliminate a lot of low concentration CO and toluene,the best way is catalytic oxidation method.And no matter what method is selected,the selection of adsorbent and catalyst is critical.In recent years,metal organic skeleton materials attracts great attention because its large specific surface area,adjustable structure,stable performance characteristics.Therefore,Mn-BTC is selected as a template to get MnOx catalysts in this paper,MnOx catalyst was studied in different temperature area systematacially on the activity of CO oxidation species.In addition,different morphology of Mn-MOFs was synthesized and the role of different shape of Mn-MOFs adsorbent in toluene adsorption reaction is studied.1.A comprehensive study was carried out on amorphous metal-organic frameworks Mn-MIL-100 as efficient catalysts towards CO oxidation.This part of the study focuses on explaining the crystalline-amorphous-crystalline transformations during thermolysis process of Mn-MIL-100 and studying the structure changes during the reaction process for CO oxidation.A possible formation mechanism of amorphous Mn-MIL-100 was proposed.Amorphous Mn-MIL-100 obtained by calcination at 250°C?a-Mn-250?showed a smaller specific surface area?4 m²/g?,but displayed a high catalytic activity.Furthermore,the structure of amorphous Mn-MIL-100 was labile during the reaction process.When used a-Mn-250 were treated with reaction atmosphere at high temperature?named used a-Mn-250-S?,the amorphous catalysts transformed to Mn₂O_3.Meanwhile,BET surface area?164 m²/g?and the catalytic performance both sharply increased.A schematic of the structure changes during the reaction process was proposed.The achievement of our synthesis relies on the increase of BET surface area using CO as retreatment atmosphere,and the enhanced catalytic activity was attributed to the unique structure,a high quantity of surface active oxygen species,oxygen vacancies and good low temperature reduction behavior.2.In this work,metal-organic frameworks?MOFs?Mn-MIL-100 were first prepared,which were next used as templates to obtain the irregular porous Mn₂O₃ cubes through calcination with air at different temperature.The catalysts were characterized by N₂ adsorption-desorption,X-ray diffraction?XRD?,scanning electron microscope?SEM?,transmission electron microscopy?TEM?,H₂-temperature program reduction?H₂-TPR?and X-ray photoelectron spectroscopic?XPS?.The catalytic activity for CO oxidation over Mn₂O₃ catalysts was investigated.It was found that calcination temperature had a strong effect on the structure and catalytic activity of Mn₂O₃ catalyst.Mn₂O₃ catalyst obtained by calcined at 700 ^oC?Mn₂O₃-700?showed a smaller specific surface area,but displayed a high catalytic activity and excellent stability with a complete CO conversion temperature(T₉₈)of 240 ^oC,which was attributed to the unique structure,a high quantity of surface active oxygen species,smaller particle size,oxygen vacancies and good low temperature reduction behavior.The effect of water vapor on catalytic activity was also examined.The introduction of water vapor to the feedstock induced a positive effect on CO oxidation over Mn₂O₃-700 catalyst.3.Through controlling the experimental method and experimental variables,using hydrothermal method to make several different morphology of Mn-MOFs adsorbents,finding out the best adsorbent in toluene adsorption.The results show that the ability of spherical adsorbent adsorbing toluene is best.And it is found that pores in the composite structure is ideal adsorption material,the hole is conducive to molecular diffusion,and microporous conducive to molecular adsorption,the greater of micropore volume,the better of adsorption performance.