Zeolites Na-A and Na-X are important synthetic zeolites widely used for separation and adsorption in industry. It is of great significance to develop energy-efficient routines that can synthesize zeolites Na-A and Na-X from low-cost raw materials. Coal fly ash (CFA) is the major residue from the combustion of coal and biomass containing more than 85% SiO2 and Al2O3, which can readily replace th...

Using the chemical reduction method, silver nanoparticles (Ag NPs) were effectively synthesized into the zeolite framework in the absence of any heat treatment. Zeolite, silver nitrate, and sodium borohydride were used as an inorganic solid support, a silver precursor, and a chemical reduction agent, respectively. Silver ions were introduced into the porous zeolite lattice by an ion-exchange pa...

Coal gasification (IGCC) and pulverised coal combustion (PCC) fly ashes (FAs), obtained from two power plants fed with the carboniferous bituminous coal from Puertollano (Spain), were characterized. Both FAs were used as raw materials for zeolite synthesis by direct conversion and by alkaline fusion, and SiO2 extraction at laboratory scale. The Puertollano FAs are characterised by a high SiO2 c...

Zeolites are crystalline inorganic porous materials formed by TO4 tetrahedra (T=Si, Al, P, etc.) with ordered microporous structures. As a result of their tunable acidities and framework structures, zeolites have been used widely in catalysis and molecular adsorption/separation as well as several other emerging applications. However, the pore size of a zeolite is usually smaller than 2 nm, whic...

A new SUZ-4 zeolite membrane with tetraethlyammonium hydroxide as the template was fabricated on mullite tube via hydrothermal sol-gel synthesis in a rotating autoclave reactor. The suitable synthesis condition was SiO2:Al2O3 ratio of 21.2 for 4 days at 155 °C crystallization under autogenous pressure. The obtained SUZ-4 possessed a high BET surface area of 396.4 m/g, total pore volume at 2.611...

An overview of the synthesis, characterization and catalytic applications of polyoxometalates/zeolites composites is given. The solids obtained by direct synthesis of the polyoxometalate in the presence of the zeolite are first described with their applications in catalysis. Those obtained by a direct mixing of the two components are then reviewed. In all cases, special care is taken in the loc...

−− The objective of this work was to synthesize zeolitic products using rice husk ash (RHA) as silicon source. For the synthesis, two mineralizing agents: NaOH and KOH were tested. Chemical composition of the synthesized samples as well as their cation exchange capacity (CEC) were determined. The samples were also characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). ...

In this work, perlite was used as a low-cost source of Si and Al in the synthesis of sodalite zeolite using hydrothermal synthesis method. Cu2O nanoparticles were coated on a bed of sodalite zeolite and used as an adsorbent for removal of diazinon from aqueous solutions. To analyze the process, a significant variable .i.e. removal efficiency (%) of diazinon and three dependent parameters as the...

The permeability of reverse osmosis membranes is limited by the diffusive transport of water across a non-porous polyamide active layer. Alternatively, fabricating a microporous active layer capable of rejecting salt ions while allowing for water transport would increase the permeability while maintaining high salt rejection. Zeolites provide a model porous network which is capable of performin...