Ketone-group containing condensed organic molecules supported on SBA-15 for the oxidative dehydrogenation of ethylbenzene to styrene

To make clear the catalytic activity centers for the metal-free catalysts is of key importance for the further development of metal-free catalysts and understanding the metal-free catalytic reactions. The single ketone and diketone group containing catalysts with extremely low metal content were prepared for exploring the relationship between the types of functional groups in the catalysts and their catalytic performance. Both single ketone and diketone groups can play the role of active centers for catalytic oxidative dehydrogenation of ethylbenzene (ODH of EB) to styrene. More importantly, the activity of diketone group based catalyst was about two times of that of single ketone group based catalyst under proper test condition. The apparent activation energy of diketone-based catalysts reached 86 kJ center dot mol-1, and that of single ketone group was 114 kJ center dot mol-1. The hydrogen transfer from ethylbenzene to ketone groups may be the critical step for the oxidative dehydrogenation of ethylbenzene to styrene.

Automated summary

Clearing the catalytic activity centers is crucial for developing metal-free catalysts and understanding their reactions. In the case of oxidative dehydrogenation of ethylbenzene to styrene, both single ketone and diketone groups can act as active centers, with the diketone-based catalyst showing higher activity. The transfer of hydrogen from ethylbenzene to ketone groups is likely a key step in the reaction.