Hydrogenation Performance Of Ni/SBA-15 And Ni/Al-SBA-15 Catalysts On Maleic Anhydride

The hydrogenation of maleic anhydride can produce a series of widely used chemicals, such as succinic anhydride, y-butyrolactone, tetrahydrofuran, 1,4-butanediol, etc. How to prepare a catalyst with high active and high selective hydrogenation performance of maleic anhydride is widely studied. Among all the factors, crystallite size of active metal component and surface acidity can play an important effect on the catalytic performance of catalyst. Previous studies demonstrated that smaller crystallite size of metal component have higher metal surface area and higher hydrogenation activity. While moderate surface acidity can promote the hydegenation of C=O in maleic anhydride meolecue and produce deep-hydrogenation product.Modified material Al-SBA-15 not only can maintain regular two-dimensional pore structure of hexagonal, but also can regulate the acidity of catalyst by changing silica to alumina ratio. It can significantly improve the contact area of reactants with the active center, and can regulate the activity of a metal or metal oxide crystallite size, and increase the catalytic activity of the catalyst.Based on this, we used SBA-15 and Al-SBA-15 as a support and citric acid complexing agent is introduced during the preparation of the catalyst. The effect of crystallite size of Ni and surface acidity on the catalytic performance of catalyst were investigated. The results can provide guidance for the development of highly effective catalyst for maleic anhydride. The main research contents are showed as follows:1. CA-Ni/SBA-15 catalyst was prepared by the introducing citric acid in the process of preparing catalyst compared with no citric acid catalyst. Characterization means such as XRD, BET, TEM were used to characterize the catalytic performance for maleic anhydride hydrogenation. The results showed that citric acid moleculecan coordinate with metal Ni and promote the dispersionof active component which locating on the surface of the support, and catalyst CA-Ni/SB A-15 showed a high ability of hydrogenation.2.The Al-SBA-15 with different acidic properties were prepared by introducing aluminum source and used in hydrogenation of maleic anhydride. XRD, H2-TPR, NH3-TPD characterization methods were used to characterize catalysts. Research results showed that with the silica alumina ratio decreased, the amount of surface acidity of catalysts increased, and the dispersion of active components is decreased accordingly. With the silica alumina ratio of 10, Ni/Al-SBA-15 showed the highest selectivity to y-butyrolactone.