Study On Preperation, Characterization And Application Of Pd/γ-Al₂O₃/Cordierite Monolith Catalyst

Recently, chemical process is sustainability developed toward safely, compactly, efficiently and environmental friendly. It is proposed to strengthen catalytic process through the development of new technologies in chemical engineering and new equipment to enhance the chemical process. Structural characteristics of the catalyst in the catalyst structure, parallel to each other because of the carrier channel, which makes the structure of the active component of catalyst and reaction gas contacts become very easy, but also reduce the pressure drop inside the reactor has played a facilitating role. At present, the structured catalyst supports offer plenty of advantages over traditional catalyst supports and now become the most attractive installations in industrial catalysis process, owing to its low bed pressure, well heat and mass transfer performance, high catalyst utilization efficiency and so on. Favourable catalyst and corresponding reactor can greatly improve the efficiency of the reaction,therefore,application of structured catalysts prospects are bright. In this thesis, the coating technique of theγ-Al₂O₃ based washcoats on surface of cordierite honeycomb substrate was investigated, so as to achieve increased surface area of the structured carrier and improve reaction efficiency and selectivity, And prepares the structurized catalyst under the dissimilar condition.Meanwhile,therelationship of the preparation-structure-performance was also studied on catalytic hydrogenation of m-phenylenediamine.Well-definedγ-Al₂O₃ coated monoliths with cordierite monolith to be used in the preparation of structured catalysts have been prepared so as to achieve increased surface area, the structured catalyst have been prepared immersion method. The factors of Pd content ,roasting temperature,reduction temperature ,additives content and reaction time were investigated. Crystal ,BET surface area, microstructure, ,reduction property were also investigated by XRD,BET, TEM and H₂-TPR. The results showed that the content of Pd is less, The specific surface area is small, catalyst Adopt excessive impregnation method is larger, the catalyst prepared content and the increase of active components Pd particles gradually increasing, reduction temperature gradually reduced. The best Catalyst preparation conditions is that, Pd content is 0.5%, roasting temperature is 773K, reduction temperature is 623K.The influence of reaction temperature, pressure,time, additives and Additives content on catalytic hydrogenation was investigated. It showed that the best reaction temperature is 373K, pressure is 3.0 MPa, fertilizer could improve catalyst activity, the best Pd: Pt is 2:1.