While microwave enhancement of chemical syntheses has been demonstrated for a broad variety of chemical reactions, there is no accepted universal mechanism. Is the enhancement due to more efficient heating, to overheating, to nonuniform heating, or to nonthermal effects? Analyses are complicated due to the often significant spatial and temporal temperature variations in microwave reactor system...

The ion exchange of Na for Cr/K, Cr/Mg and Cr/Ca in Y and X zeolites was studied using breakthrough curves. It was observed that Cr ions were able to remove some competitive ions that had already been exchanged at the zeolitic sites, producing a sequential ion exchange. Some mass transfer parameters such as length of unused bed, overall mass transfer coefficient, operational ratio and dimension...

Methanol is an important feedstock in numerous catalytic processes. It can be produced via Fischer-Tropsch reaction from synthesis gas [1] and its further transformation to hydrocarbons up to C10 is the basis of several industrially important reactions as for instance the Methanol to Gasoline process [2]. Methanol can also be used as an alkylating agent for aromatic compounds in zeolite-catalys...

The investigation on the modification of NaY zeolite on LaHY and AEHY (AE refers Ca and Sr and the molar ratio of Ca and Sr is 1:1) zeolites was proformed by XRD, N2-physisorption (BET), XRF, XPS, NH3-TPD, Py-IR, hydrothermal stability, and catalytic cracking test. These results indicate that HY zeolite with ultra low content Na can be obtained from NaY zeolite through four exchange four calcin...

In this work, zeolite NaY was prepared by hydrothermal method. Then, silver ions were replaced in the zeolite NaY with silver nitrate (AgNO3) solution via using ion exchange (IE) method. The Manganese dioxide (MnO2) nanoparticles (9.3 and 15.8 wt %) for guest were deposited in the zeolite AgY(host) structure with Mn(NO3)2 aqueous and KMnO4 solutions by confined space synthesis (CSS) metho...

We focus on the analysis of N(2) adsorption on NaY faujasite investigated by means of both the FTIR and volumetric measurements. We examine how these two approaches, when combined, can lead to a more advanced quantitative description featuring the understanding of gas adsorption both at the molecular and the macroscopic scales. For this task, we describe hereafter the method used and how we cir...

The spin-lattice relaxation time T\ of 2 , N a N M R in dehydrated zeolite NaY has been measured from 26 to 300 K. The magnetization recovery curve is not single-exponential at all measured temperatures and 1 increases in proportion to the square of temperature above 200 K. The result is analyzed with a theory of the Raman process based on covalency. The value of T\ is compared with that of NaX...

Organometallic complexes hosted inside porous frameworks are particularly interesting because of possible application in heterogeneous catalysis or electronic devices and optical materials. We present here a detailed spectroscopic investigation on the structure and reactivity towards simple reagents (such as CO) of chromocene molecules (Cp2Cr) encapsulated into the nanovoids of two different ma...

ZSM-5- and NaY-coated MCF materials as new acid catalysts for conversion of bulky molecules were prepared by the coating procedure using diluted clear zeolite gel solutions. The resulting materials have high acidity and improved steam stability as compared to that of the corresponding MCF aluminosilica. This could be due to the zeolitic nature and relative hydrophobicity of the mesopore surface.

A sodiothermic reduction method has been developed for the preparation of porous silicon using aluminosilicate zeolite NaY as a precursor. The porous silicon with a specific surface area of approximately 570 m(2) g(-1) shows distinct capacitive behavior when used as an electrode material for supercapacitors.