Epoxidation of 1-octene under harsh tail-end conditions in a flow reactor II: impact of delaminated-zeolite catalyst surface area and structural integrity on catalytic performance
Epoxidation of 1-octene under harsh tail-end conditions in a flow reactor II: impact of delaminated-zeolite catalyst surface area and structural integrity on catalytic performance
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流动反应器 II 中恶劣尾端条件下 1-辛烯的环氧化：分层沸石催化剂表面积和结构完整性对催化性能的影响
DOI：
10.1039/c7re00138j
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发表时间：
2017
影响因子：
3.9
通讯作者：
A. Katz
中科院分区：
文献类型：
--
作者：
M. Aigner;N. A. Grosso-Giordano;C. Schöttle;A. Okrut;S. Zones;A. Katz
基于我们以前在环氧化流动反应器中使用有机过氧化氢作为氧化剂的苛刻尾端条件下的脱层沸石催化剂的研究，本文比较了催化剂制备中的脱层方法。在一种方法中，使用温和的脱层方法合成Ti-UCB-4，其中有机溶剂中的氟化物用作矿化剂以影响脱层，而在另一种方法中，通过在高pH条件下脱层合成催化剂Ti-SSZ-70-DEL-HIGHPH，并导致最高的外表面积，类似于先前报道的ITQ-2。我们还将两种材料与由Ti-SSZ-70组成的煅烧的3-D沸石进行比较，所述煅烧的3-D沸石是未经历脱层处理的对照。长期流动反应器催化测试的结果表明，相对于3-D Ti-SSZ-70，Ti-UCB-4的反应速率常数k '以质量计明显增加2.5倍，并且两种催化剂都没有长期失活。相比之下，对于Ti-SSZ-70-DEL-HIGHPH，由于失活，没有观察到转化率或选择性随运行时间增加的稳态行为。来自粉末X射线衍射（PXRD）、77 K下的氮物理吸附、高角度环形暗场扫描透射电子显微镜（HAADF-STEM）和紫外可见（UV-vis）光谱的数据的组合证明Ti-SSZ-70-DEL-HIGHPH由结晶相和非晶相的组合组成。对照实验表明，当两相在单一催化剂中组合时，对催化的负协同作用，这导致转化率降低，其水平低于基于存在的两相的线性组合预测的值。
Building on our previous study of delaminated-zeolite catalysts for harsh tail-end conditions in an epoxidation flow reactor employing organic hydroperoxide as oxidant, this manuscript compares approaches for delamination in catalyst prepration. In one, a mild method of delamination is used for synthesis of Ti-UCB-4, in which fluoride in organic solvent is used as a mineralizing agent to affect delamination, while in another, catalyst Ti-SSZ-70-DEL-HIGHPH is synthesized by delamination under high-pH conditions and results in the highest external surface area, similar to that previously reported for ITQ-2. We also compare both materials to the calcined 3-D zeolite consisting of Ti-SSZ-70, a control which underwent no delamination treatment. Results of long-term flow reactor catalytic testing demonstrate a distinct 2.5-fold increase in reaction-rate constant k′ on a mass basis for Ti-UCB-4 relative to 3-D Ti-SSZ-70, and a lack of long-term deactivation for both catalysts. In contrast, for Ti-SSZ-70-DEL-HIGHPH, due to deactivation, no steady-state behavior is observed for either conversion or selectivity with increasing times on stream. A combination of data from powder X-ray diffraction (PXRD), nitrogen physisorption at 77 K, high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and UV-visible (UV-vis) spectroscopy demonstrate Ti-SSZ-70-DEL-HIGHPH to be comprised of a combination of crystalline and amorphous phases. Control experiments demonstrate a negative synergy on catalysis when both phases are combined in a single catalyst, which leads to decreased conversion, at levels below values predicted based on the linear combination of the two phases present.
通过壳牌 SMPO 工艺进行丙烯环氧化：30 年的研究和运营
DOI：
--
发表时间：
2008
期刊：
影响因子：
--
作者：
J. Buijink;J. Lange;A. Bos;A. Horton;F. Niele
通讯作者：
F. Niele
影响因子：
5.2
作者：
Corma, A;Fornés, V;Buglass, JG
通讯作者：
Buglass, JG