负载型杂多酸上乙烷氧化脱氢反应途径

REACTION MECHANISM OF ETHANE OXIDATIVE DEHYDROGENATION

以 O2 为氧化剂 ,以负载在 Si O2 上的 Keggin型杂多酸为催化剂 ,研究了催化剂酸性和 TPR曲线特性对乙烷氧化脱氢反应活性的影响 ,并探讨了相关反应机理和具体反应途径 .研究发现 :乙烷氧化脱氢反应主要产物是乙烯、一氧化碳和二氧化碳 ;反应以气相自由基反应为主 ,伴随有表面反应的发生 ;催化活性受弱酸性和 TPR曲线特性的影响较大 ,酸性越强 ,反应的起燃温度越高 ,具有适宜 TPR还原峰温的催化剂反应活性最好 .

The influence of acidity and redox properties of silica supported heteropolyacids (HPAs) on the catalytic performance was examined with O 2 as oxidant. The reaction mechanism and pathways were also discussed. It was observed that the main products of ethane oxidative dehydrogenation were ethene, carbon monoxide and carbon dioxide. Gasphase radical reaction was the main pathway, but the surface reaction took place simultaneously. The stronger the acidity was, the higher the light off temperature of radical reaction was. The catalyst with a suitable redox property gave the best result of ethane oxidative dehydrogenation.