Catalytic performance of boron and aluminium incorporated ZSM-5 zeolites for isomerization of styrene oxide to phenylacetaldehyde

• [B]-[Al]-ZSM-5 zeolites with different acid properties were evaluated.
• The weakly acidic B-ZSM-5 can enable the reaction to be carried out at high activity.
• The stability of B-ZSM-5 depends on weak acid concentration and coordination of B.
• The incorporation of B in Al-ZSM-5 enhances the stability remarkably.
• The weak acid sites will not lead to the formation of 1,3,5-triphenylbenzene.

A series of boron and aluminium incorporated ZSM-5 catalysts were synthesized to study the performance of styrene oxide isomerized to phenylacetaldehyde. The physicochemical properties were characterized by a combination of nitrogen adsorption, in situ IR, XRD, SEM, NMR (27Al, 29Si, 11B), NH3-TPD and TG-DTA. The weak acidity of B containing ZSM-5 zeolites is sufficient to facilitate the reaction at high initial conversion and selectivity, but the stability of the catalysts relies heavily on the concentration of weak acid sites and the properties of strong acid sites. It is implied that the incorporation of B into Al-ZSM-5 influences the distribution of Al in the framework and has promoting effect on the stability of the catalysts. 1,3,5-Triphenylbenzene was not detected with increased concentration of weak acids, indicating that the weak acid sites will not lead to its formation. BAlZ-2 shows the best performance at 300 °C without deactivation after 120 h on stream.

Figure optionsDownload as PowerPoint slide