نتایج جستجو برای: hierarchical zeolites
تعداد نتایج: 96710 فیلتر نتایج به سال:
In this paper, conventional SAPO-34 and Cerium Hierarchical SAPO-34 zeolites are synthesized using a hydrothermal method for methanol-to-propylene (MTP) reaction. The Ce-H-SAPO-34 catalyst shows a slightly larger crystal size, bimodal pore size distribution (microporous and mesoporous) and lower surface acidity compared to conventional SAPO-34 catalysts. According to these physicochemical prope...
A novel methodology, called ADOR (assembly-disassembly-organisation-reassembly), for the synthesis of zeolites is reviewed here in detail. The ADOR mechanism stems from the fact that certain chemical weakness against a stimulus may be present in a zeolite framework, which can then be utilized for the preparation of new solids through successive manipulation of the material. In this review, we d...
In this Account strategies using zeolites as media to achieve chiral induction are presented. Diastereomeric excesses as high as 90% and enantiomeric excesses up to 78% have been obtained with selected systems within zeolites. The same systems show no asymmetric induction in solution. Chiral induction is dependent on the alkali ions present in the zeolites. Alkali ions control not only the exte...
Zeolites are an important class of materials that have wide ranging applications such as heterogeneous catalysts and adsorbents which are dependent on their framework topology. For new applications or improvements to existing ones, new zeolites with novel pore systems are desirable. We demonstrate a method for the synthesis of novel zeolites using the ADOR route. ADOR is an acronym for Assembly...
Cation exchange capacity (CEC) is an important characteristic of zeolites, especially when they are used as adsorbents in the aqueous system. However, no international standard method exists for the determination of CEC of zeolites. We determined CEC of Linde-type A and Na-P1 type zeolites at various pH (4 to 10) with a simple method, where Na+-saturated zeolites were prepared, and then various...
We report the advances in the principal structural and experimental factors that might influence the carbon dioxide (CO2) adsorption on natural and synthetic zeolites. The CO2 adsorption is principally govern by the inclusion of exchangeable cations (countercations) within the cavities of zeolites, which induce basicity and an electric field, two key parameters for CO2 adsorption. More specific...
Zeolites as Carriers of Nano-Fertilizers: From Structures and Principles to Prospects and Challenges
The world is facing immense challenges in terms of food security, due to the combined impacts ever-increasing population and adversity climate change. In an attempt counteract these factors, smart nutrient delivery systems, including nano-fertilizers, additives, material coatings, have been introduced increase productivity meet growing demand. Use nanocarriers agro-practices for sustainable far...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید