First-Principles Study of Interface Structures and Charge Rearrangement at the Aluminosilicate/Ru(0001) Heterojunction

Aluminosilicate bilayer films consisting of corner-sharing [SiO ₄ ] and [AlO ₄ ] tetrahedra on a metal substrate are important model systems to study zeolite chemistry in heterogeneous catalysis. Understanding the interfacial electronic properties of the aluminosilicate/metal heterojunction is a fundamental step to rationalize the structure-property-function relationship essential to the catalytic activities of the model zeolite. In this work, we use density functional theory (DFT) to investigate the charge rearrangement at the aluminosilicate/Ru(0001) interface, which is attributed to hybridizations between the O p _z and Ru dz ² and s orbitals and the subsequent electron redistribution. We found that the energy level alignment at the aluminosilicate/Ru(0001) heterojunction is determined by the surface and interface dipole moments resulting from the charge rearrangements and that the magnitude of these dipole moments can be modified by the aluminum concentration and the surface O coverage on Ru(0001).