Dealumination, silicon insertion and H-proton exchange of NaY in one step with acid ethanol solution

Abstract

A new strategy to dealumination, silicon insertion and H-proton exchange of NaY in one step with acid ethanol solution is reported in this article. The removal of framework aluminum is controlled by modulating the acid through adjusting the water amounts in the ethanol, and the formed cationic non-framework aluminum species are solved in the solution by complexation with hydroxy carboxylate. Substitution of framework silicon for aluminum (stabling the zeolite structure) and the H-proton exchanges with sodium are completed in this dealumination process simultaneously. By using tartaric acid as leaching agent in ethanol solution, 78% of the framework aluminum atoms can be released with 94% exchange of the sodium cations in this dealumination process. This new strategy displays two advantages: firstly, excluding the NH4+ pollution by using acid to exchange sodium cation directly, and secondly, energy- and time-saving by combining the dealumination, silicon insertion and H-proton exchange in one step.