نتایج جستجو برای: ni zsm 5 nanozeolite

تعداد نتایج: 1262176  

ژورنال: مواد نوین 2014

نانو SiC متخلخل با سطح ویژه بالا می‌تواند به عنوان پایه کاتالیست و هم­چنین، جهت بهینه نمودن فرآیند زینترینگ بدنه‌هایSiC بکار گرفته شود در این پژوهش بمنظور سنتز SiC متخلخل ابتدا میکرو‌حفره زئولیت ZSM-5 سنتز گردید. سپس عامل کربنی فورفوریل الکل درون حفرات زئولیت ZSM-5 تلقیح شد و نانو کامپوزیت زئولیت ZSM-5/فورفوریل الکل دراتمسفر آرگون و در دمای˚C 900 با زمان ماندگاری شش ساعت در درجه حرارت بیشینه کر...

Journal: :Catalysis Today 2021

The characterization and catalytic performance of Zn/ZSM-5 Zn-B/ZSM-5 catalysts in the n-hexane aromatization was reported. Catalysts were prepared by post-synthesis ion exchange thoroughly characterized means XRD, Py-FTIR, N2 adsorption, 27Al 11B MAS NMR spectroscopy electron microscopy techniques. incorporation zinc reduces Brønsted acid site density increases Lewis acidic sites final ZSM-5 b...

2006
Xiaobo Zheng Alexis T. Bell

Dimethyl carbonate (DMC) and dimethoxy methane (DMM) are of commercial interest because they are good fuel additives and building blocks for organic synthesis. Both products can be produced using Cu-exchanged ZSM-5 and Y from a mixture containing O2, CO, and CH3OH. Experimental studies done in our research group [1,2] have shown that at identical reaction conditions, very different product sele...

Journal: :Chemphyschem : a European journal of chemical physics and physical chemistry 2013
Sudarat Yadnum Saowapak Choomwattana Pipat Khongpracha Jakkapan Sirijaraensre Jumras Limtrakul

The density functional theory (DFT) model ONIOM(M06L/6-311++G(2df,2p):UFF was employed to reveal the catalytic activity of Cu(II) in the paddle-wheel unit of the metal-organic framework (MOF)-505 material in the Mukaiyama aldol reaction compared with the activity of Cu-ZSM-5 zeolites. The aldol reaction between a silyl enol ether and formaldehyde catalyzed by the Lewis acidic site of both mater...

Journal: :Catalysts 2022

To improve the yield of propylene in fluidized catalytic cracking, a series different Au/ZSM-5-TOS catalysts were prepared by modifying ZSM-5, using an external surface modification method and Au nanoparticles. The modified catalyst maintained MFI structure whereas pore-opening size zeolite relatively decreased, without affecting its internal structure. acidity especially Brønsted acidity, redu...

Journal: :Journal of environmental sciences 2011
Bo Zhang Yongan Lu Hong He Jianguo Wang Changbin Zhang Yunbo Yu Li Xue

The adsorption and desorption of N2O on main-group ion-exchanged ZSM-5 was studied using temperature-programmed desorption (TPD) and density functional theory (DFT) calculations. TPD experiments were carried out to determine the desorbed temperature Tmax corresponding to the maximum mass intensity of N2O desorption peak and adsorption capacity of N2O on metal-ion-exchanged ZSM-5s. The results i...

Journal: :Silicon 2022

Hierarchical micro-mesoporous ZSM-5 (MFI type) zeolite was synthesized by using corn plant stem pith powder from agricultural waste as hard template under simple hydrothermal method. The additional porosity generated this into the zeolites precursor gel yielded hierarchical (C-ZSM-5). Conventional micro porous (ConvZSM-5) also prepared same procedure without adding to compare catalytic performa...

1999
Zhijiang Li Maria Flytzani-Stephanopoulos

The promotion of Ag–ZSM-5 by cerium for the selective catalytic reduction (SCR) of NO with methane in the presence of an excess of oxygen was studied in this work. Ce–Ag–ZSM-5 catalyzes the CH4-SCR of NOx over the temperature range of 450–600◦C. Rate measurements of NO reduction to N2 under SCR conditions and of the competing CH4 oxidation by O2 (CH4 combustion) show that incorporation of a sma...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تبریز - دانشکده شیمی 1388

در میان انواع تکنیک های حذف ترکیبات آلی فرار ، یکی از مناسبترین روش ها ، روش اکسایش کاتالیستی می باشد. ولی غیرفعال شدن کاتالیست ها در طول اکسایش کاتالیتیکی ترکیبات آلی فرار یکی از مسائل مهم می باشد. در این پروژه رفتارغیرفعال شدن کاتالیستهای mn-zsm-5 و cr-zsm-5 در طول اکسایش اتیل استات و ایزو پروپانل ، همچنین احیای این کاتالیست ها با هوای سنتزی بررسی شده است. نتایج نشان می دهد که تشکیل کک باعث غ...

Journal: :Acta crystallographica. Section B, Structural science 2005
Koji Nishi Akira Hidaka Yoshinobu Yokomori

The structure of a high-loading complex of ZSM-5 with 6.4 toluene molecules per unit cell has been determined by single-crystal X-ray diffraction. At least three kinds of toluene molecules were identified in the unit cell. Two disordered toluene molecules were located at the intersection of the straight and sinusoidal channels, the third in the sinusoidal channel. One (TOL1) of the two toluene ...

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