Trimodal Porous Hierarchical SSZ-13 Zeolite with Improved Catalytic Performance in the Methanol-to-Olefins Reaction
Trimodal Porous Hierarchical SSZ-13 Zeolite with Improved Catalytic Performance in the Methanol-to-Olefins Reaction
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DOI：
10.1021/acscatal.5b02480
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发表时间：
2016-04-01
期刊：
影响因子：
12.9
通讯作者：
Hensen, Emiel J. M.
中科院分区：
文献类型：
--
作者：
Zhu, Xiaochun;Hofmann, Jan P.;Hensen, Emiel J. M.
通过在SSZ-13沸石的合成中添加二季铵型表面活性剂C22-4-4阳离子和氟阴离子，合成了具有三峰孔隙率（CHA骨架的天然微孔、类似于0.5nm的较大微孔的附加网络和中孔）的菱沸石。分级SSZ-13沸石是完全结晶的，并且表现出与本体SSZ-13沸石相似的酸性。通过大分子的吸收实验和噻吩低聚物的选择性染色证明，在分级SSZ-13中增加的扩散速率导致甲醇制烯烃（MTO）反应中的催化剂失活慢得多。共焦荧光图像显示的分层SSZ-13沸石的均匀分布的碳沉积物，表明在MTO反应过程中的碳空间已被完全利用。
Chabazite zeolites with trimodal porosity (native micropores of the CHA framework, an additional network of larger micropores of similar to 0.5 nm, and mesopores) were synthesized by adding diquarternary ammonium type surfactant C22-4-4 cations and fluoride anions in the synthesis of SSZ-13 zeolite. The hierarchical SSZ-13 zeolites are fully crystalline and exhibit similar acidity as bulk SSZ-13 zeolite. The increased diffusion rate in the hierarchical SSZ-13, proven by uptake experiments of bulky molecules and selective staining by thiophene oligomers, resulted in much slower catalyst deactivation in the methanol-to-olefins (MTO) reaction. Confocal fluorescent images of spent hierarchical SSZ-13 zeolites reveal homogeneous distribution of carbonaceous deposits, indicating that the micropore space has been completely utilized during the MTO reaction.