Ethane Ammoxidation over Sn/H-Zeolite Catalysts: Toward the Factors Contributing to the Yield of Acetonitrile

Authors：Liu, Yan; Li, Tingting; Qiao, Shilei; Heng, Zhongchao; Zhao, Tianyu; Wu, Huicai; Xiong, Ting; Li, Jingyue; Yao, Xingyue; Long, Liling; Xiang, Yuqin; Liu, Qian; Lu, Lijun; Liang, Tingyu^*; Chen, Jialing^*; Jin, Fang^*

Source：ACS applied materials & interfaces, 2023, 15(21): 25604-25614.

DOI：10.1021/acsami.3c04005

• ethane to acetonitrile
• reaction mechanism
• Sn-zeolite catalysts
• ammonia pool
• Lewis acidsites

Different Sn/H-zeolite (beta, MOR, SSZ-13, FER, andY zeolite)catalysts are prepared with the improved impregnation method. Theeffects of reaction temperature and the composition of the reactiongas (ammonia, oxygen, and ethane) on the catalytic reaction are investigated.Adjusting the fraction of ammonia and/or ethane in the reaction gascan effectively strengthen the ethane dehydrogenation (ED) route andethylamine dehydrogenation (EA) route and inhibit the ethylene peroxidation(EO) route, whereas the adjustment of oxygen cannot effectively promoteacetonitrile formation because it cannot avoid enhancing the EO route.By comparing the acetonitrile yields on different Sn/H-zeolite catalystsat 600 degrees C, it is revealed that the ammonia pool effect, the residualBro''nsted acid in the zeolite, and the Sn-Lewis acid synergisticallycatalyze ethane ammoxidation. Moreover, a higher L/B ratio of theSn/H zeolite is beneficial to the improvement of acetonitrile yield.With a certain application potential, the Sn/H-FER-zeolite catalystshows an ethane conversion of 35.2% and an acetonitrile yield of 22.9%at 600 degrees C; although a similar catalytic performance was observedon the best Co-zeolite catalyst in literature, the Sn/H-FER-zeolitecatalyst is more selective to ethene and CO than the Co catalyst.In addition, the selectivity to CO2 is less than 2% ofthat on the Sn-zeolite catalyst. This may be attributed to the special2D topology and pore/channel system of the FER zeolite, which guaranteean ideal synergistic effect of the ammonia pool, the residual Bro''nstedacid in the zeolite, and the Sn-Lewis acid for the Sn/H-FER-catalyzedethane ammoxidation reaction.

• Institution
  武汉工程大学