Abstract: Zeolite HZSM-5 calcined at different temperatures were studied by29Si MAS NMR and EPR method. It was concluded that in certain temperature range, dealumination did not necessarily occur simultaneously with f...Abstract: Zeolite HZSM-5 calcined at different temperatures were studied by29Si MAS NMR and EPR method. It was concluded that in certain temperature range, dealumination did not necessarily occur simultaneously with framework dehydroxylation and thus framework Lewis acidic sites emerged. Two processes may be operative with one of them being predominant at different temperatures.展开更多
文摘Abstract: Zeolite HZSM-5 calcined at different temperatures were studied by29Si MAS NMR and EPR method. It was concluded that in certain temperature range, dealumination did not necessarily occur simultaneously with framework dehydroxylation and thus framework Lewis acidic sites emerged. Two processes may be operative with one of them being predominant at different temperatures.
