MTO performance over seed-assisted SAPO-34 zeolites synthesized by reducing template consumption
MTO performance over seed-assisted SAPO-34 zeolites synthesized by reducing template consumption
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DOI：
10.1016/j.jmrt.2020.08.067
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发表时间：
2020-11
期刊：
影响因子：
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通讯作者：
Sahar Akhgar;J. Towfighi;M. Hamidzadeh
中科院分区：
文献类型：
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作者：
Sahar Akhgar;J. Towfighi;M. Hamidzadeh
通过晶种诱导法制备了SAPO-34样品，大大降低了模板剂浓度。采用XRD、FESEM、EDS、N2吸附和NH3-TPD等手段对合成的SAPO-34分子筛进行了表征。样品在MTO工艺中表现出不同的催化活性，这是由于它们在物理化学性质上的差异，包括微晶/粒度、表面积、酸强度和浓度。首次将有机模板剂还原60%得到了纯的SAPO-34。然而，由于颗粒尺寸的增加，它没有显示出期望的催化性能。根据催化剂的高酸性和较大的比表面积，将模板剂用量减少40%制备的催化剂具有较好的催化性能。该样品表现出对轻质烯烃的91.8%的选择性和约330分钟的寿命，这在选择性方面比未接种的样品高14.4%，寿命是未接种的样品的两倍多。这一实质性成果是在工业进料条件（72%wt甲醇水溶液）下获得的，并且为制备具有前景的MTO催化剂提供了具有显著降低的模板剂用量的成本效益和环境友好的路线。
SAPO-34 samples were prepared via a seeding-induced method with a considerable reduction of template concentration. The resultant SAPO-34 zeolites were investigated by XRD, FESEM, EDS, N2adsorption, and NH3-TPD analyses. The samples represent different catalytic activity in the MTO process due to their differences in the physic-chemical properties, including crystallite/particle sizes, surface area, acid strength and concentration. Pure SAPO-34 was obtained with a 60% reduction of organic template for the first time. However, due to the increase of particle sizes, it did not show the desired catalytic performance. An excellent catalytic performance was achieved for the seeding-induced catalyst prepared by a 40% reduction of template content according to its appropriate high acidity and relatively large surface area. This sample exhibited 91.8% selectivity toward light olefins and about 330 min of lifetime, which were 14.4% higher in term of selectivity and more than twice lifetime than the unseeded sample. This substantial achievement was obtained under the industrial feed conditions (72%wt methanol in water) and provided a cost-effective and environmentally friendly route for preparing promising MTO catalyst with notably decreased template dosage.