Study On Vanadium Supported By Mesoporous Al-based Oxide Catalysts For Dehydrogenation Of Ethylbenzene With CO₂

Styrene is a kind of basic petrochemicals,and a crucial monomer for the synthesis of various polymer materials,playing a very important role in the fields of petrochemical industry and polymer materials production.Currently,the vast majority of styrene made by dehydrogenation of ethylbenzene.In industry,the process was conducted in high temperature about 600-700?,using K-doped ferric oxide as a catalyst and a large amount of superheated steam as the carrier.Hydrocarbon dehydrogenation reaction is one of the most challenging task in petrochemical industry,on account of the thermodynamic limit on equilibrium conversion rate.In recent years,the oxidative dehydrogenation reaction technology is becoming a hot spot of research,especially with carbon dioxide as oxidant.It is effective to reduce the energy consumption of reaction.At the same time,the coupling of reactions can also be achieved.The consumption of greenhouse gas CO₂ met the requirements of the development of green chemistry well.At present,many studies have been done on the Fe-based and V-based catalysts,in the process of oxide dehydrogenation of ethylbenzene with CO₂,and some results have been achieved,but satisfactory catalytic effects have not yet been done.The preparation of high-performance catalysts have important practical application value and theoretical duiding significance.In this paper,an ordered mesoporous alumina?OMA?carrier,an ordered mesoporous aluminum-zirconium?OMZA?composite oxide carrier and an ordered mesoporous aluminum-magnesium?OMMA?composite oxide were prepared by solvent evaporation self-assembly?EISA?.A series of ordered mesoporous oxides supported vanadium catalysts were prepared by traditional wet immersion?IMI?.Catalytic properties was investigated respectively.Catalysts were characterized by XRD,N₂ sorption,H₂-TPR,XRS,TG,et al.The relationship was explored between the physicochemical structure of catalyst and its catalytic performance.And the results were shown as follow:1.The catalytic performance of VOx/OMA catalyst is closely related to V-loading.When the V-loading is 0.8 mmol/g,it has a good stability and the highest conversion of ethylbenzene is 51.7%.2.Carrier structure is closely related to the catalyst performance.The0.8V/OMA catalyst showed a superior stability,compared with the 0.8V/CA catalyst.3.After the introduction of zirconia,0.8V/OMZA-X catalysts have higher ethylbenzene conversion than 0.8V/OMA.urthermore 0.8V/OMZA-8 catalyst has the highest increase of ethylbenzene conversion.