نتایج جستجو برای: natural zeolites

تعداد نتایج: 486020  

Journal: :journal of ornamental plants 2015
a. mahboub khomami

this experiment was designed to characterize the effects of size and concentration of an iranian clinoptilolite zeolite on the growth officus benjamina (starlight) in peat base media. ficus benjamina was stock rooted and grown in a peat consisting perlite (2: 1 v/v) (p: pe), zeolite (10, 20, 30 and 40 v/v %, two sizes 0.5-3 mm and 3-8 mm) instead of peat in p: pe (2: 1 v/v) media. ficus benjami...

Journal: :Molecules 2014
Moses Wazingwa Munthali Mohammed Abdalla Elsheikh Erni Johan Naoto Matsue

In addition to their well-known uses as catalysts, zeolites are utilized to adsorb and remove various cations from aqueous system. The adsorption of the cations is ascribed to the negative charge of zeolites derived from isomorphous substitution of Si by Al. The amount of Na+ adsorption on 4A, X, Y, Na-P1 and mordenite type zeolites were determined in aqueous media, in a two-cation (Na+ and H+)...

2016
Andreas Martin Keith Hohn

The Special Issue “Zeolite Catalysis” published in the online journal Catalysts was recently successfully completed. A good number of peer-reviewed publications were published reflecting the broadness of the zeolite syntheses, characterizations and various application fields. This issue brought together recent research of well-known research teams from all over the world. The term “zeolite” is ...

Journal: :Journal of computational chemistry 2009
Frederik J. Tielens

The acid-base properties of zeolites with group 5 transition metal framework sites are investigated, and a first step into the understanding of their acid/base and redox properties is undertaken using DFT reactivity descriptors. It is evidenced, using sodalite as model system, that zeolites with vanadium framework sites are more nucleophilic than zeolites with niobium and tantalum framework sit...

2004
Benoı̂t Louis Lioubov Kiwi-Minsker

ZSM-5 zeolites were prepared at neutral pH by fluoride-mediated synthesis. The degree of crystallinity, the specific surface area and the crystal size are higher than those of the zeolites prepared under alkaline conditions. Moreover, by varying the F/Si ratio from 0.3 to 1.6, the H–[F]–ZSM-5 zeolites with crystal size ranging from 10 to 75 lm and the specific surface areas from 60 up to 350 m/...

Journal: :Chemical communications 2008
Yasutaka Kuwahara Takashi Kamegawa Kohsuke Mori Hiromi Yamashita

Hydrophobically modified Y-zeolites were prepared by simple modification with triethoxyfluorosilane (TEFS). These zeolites, used as supports, enhanced the efficiency of deposited TiO(2) for the photocatalytic degradation of organics diluted in water.

2013
Kaname Yoshida Kazuaki Toyoura Katsuyuki Matsunaga Atsushi Nakahira Hiroki Kurata Yumi H. Ikuhara Yukichi Sasaki

Zeolites have potential application as ion-exchangers, catalysts and molecular sieves. Zeolites are once again drawing attention in Japan as stable adsorbents and solidification materials of fission products, such as (137)Cs(+) from damaged nuclear-power plants. Although there is a long history of scientific studies on the crystal structures and ion-exchange properties of zeolites for practical...

Journal: :Chemistry 2016
Juan José Gutiérrez-Sevillano Sofía Calero Said Hamad Ricardo Grau-Crespo Fernando Rey Susana Valencia Miguel Palomino Salvador R G Balestra A Rabdel Ruiz-Salvador

Incorporation of germanium in zeolites is well known to confer static flexibility to their framework, by stabilizing the formation of small rings. In this work, we show that the flexibility associated to Ge atoms in zeolites goes beyond this static effect, manifesting also a clear dynamic nature, in the sense that it leads to enhanced molecular diffusion. Our study combines experimental and the...

Journal: :Chemical Society reviews 2013
Karin Möller Thomas Bein

Frameworks of precisely defined pores with diameters matching the size of small molecules endow crystalline zeolites with valuable size- and shape-selectivity. Being important selective adsorbers and separators, zeolites are also indispensable as solid acids in size-selective catalysis. However, despite being extremely beneficial, micropores impose restrictions on the mass transport of reactant...

Journal: : 2021

The catalytic properties of modified synthetic (A, X, Y) and natural (MOR, Clp) zeolites have been studied in the reactions oxidative dehydrogenation butyl alcohols to corresponding carbonyl com-pounds. It has established that bimetallic zeolite catalysts show higher activity these

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید