Theoretical study of the effect of isomorphous substitution by $$\hbox {Al}^{3+}$$ and/or $$\hbox {Fe}^{3+}$$ cations to tetrahedral positions in the framework of a zeolite with erionite topology

Abstract

The isomorphous substitution of $$\hbox {Al}^{3+}$$ and/or $$\hbox {Fe}^{3+}$$ cations into the erionite zeolite framework were studied through periodic density functional theory computations. Taking as reference the Mulliken charges for siliceous framework computed in previous work (Antunez-Garcia et al. in J Mol Struct 1059:232–238, 2014), the present results show that the basicity of ERI zeolite increases when those cations are introduced into the framework. It was also observed that when at least two $$\hbox {Si}^{4+}$$ cations are isomorphically substituted by $$\hbox {Fe}^{3+}$$ in the unit cell of the erionite zeolite, it acquires magnetic properties. The results show that a specific net-spin polarization (up or down) could be correlated with particular configurations of erionite zeolite, containing ferric iron.