Silicon and aluminum sources are most important reactants in the synthesis of zeolite. The use of the silicon source has an important effect on the crystallization of zeolites. Also, it can change the properties of the end product. This work reports the influence of three common commercial silica sources such as colloidal silica (Ludox AM-30), fumed silica and water glass on the crystallinity o...

23Na MAS, 2D nutation MAS, and DOR NMR spectroscopy has been applied to characterise the location of sodium cations in dehydrated zeolite NaX (Si/Al = 1.23). The 23Na MAS NMR spectra recorded at three different magnetic field strengths were decomposed by computer simulation into five lines, which were attributed to five crystallographically distinct cation sites known from X-ray diffraction stu...

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...

In the preceding companion article, we reported high-temperature molecular dynamics (MD) simulations to trace single-molecule as well as collective mean square displacements over a range of temperatures (6001500 K) and loadings (infinite dilution to four benzenes per supercage) to evaluate respectively the selfdiffusivities and cooperative (alternatively Maxwell-Stefan) diffusivities of benzene...

Abstract Catalytic/initiated cracking of endothermic hydrocarbon fuels is an effective technology for cooling a hypersonic aircraft with high Mach number (over 5). Catalysts and initiators can promote fuel at low temperatures, increase conversion the heat sink capacity, suppress coke deposition, thereby reducing waste heat. mainly include metal oxide catalysts, noble catalysts nanoparticles, ze...