Abstract:
Bicyclohexane is a hydrogen storage reagent with high hydrogen density and low boiling point. Compared with the hydrogenation of biphenyl, the alkylation of benzene and cyclohexene to cyclohexylbenzene and hydrogenation is a promising way to prepare cyclohexane on a large scale. The research and development of high-efficiency cyclohexyl benzene hydrogenation catalyst should be further developed based on mature alkylation technology. This paper used an acidified USY molecular sieve to catalyze the alkylation of benzene and cyclohexene to cyclohexylbenzene, which achieved 100% conversion and selectivity. Furthermore, Pt/TiO
2/γ-Al
2O
3 catalyst is prepared by pre-deposition TiO
2 film of different thicknesses on γ-Al
2O
3 surface and then supported with platinum particles by Atomic layer deposition (ALD). The role of TiO
2 film in improving the cyclohexylbenzene hydrogenation performance of the catalyst is studied. TEM, CO pulse chemisorption, CO-DRIFTs, quasi-
in situ XPS, H-D exchange, and H
2-TPR characterization show that compared with Pt/γ-Al
2O
3, TiO
2 thin films on Pt/TiO
2/γ-Al
2O
3 do not change the dispersion of Pt particles, but can form new Pt-TiO
2 interactions. The hydrogenation performance of cyclohexylbenzene was improved by increasing the electron density and the proportion of planar active sites on the surface of platinum and reducing the energy barrier of hydrogen spillover. The research provides theoretical support for further bicyclohexane organic liquid hydrogen storage reagent development. The relevant metal-support interaction regulation strategy can be applied to the development of efficient catalysts for other aromatic molecules hydrogenation.