Quantum chemical prediction of the adsorption conformations and dynamics at HCOOH-covered ZnO(101̄0) surfaces

Abstract

Results from ab initio Hartree-Fock and gradient-corrected density functional theory calculations of formic acid interactions with ZnO (101̄0) surfaces are reported. Surface relaxation is found to affect equilibrium geometries and adsorption energies significantly. Large variations in adsorption energy with coverage and ordering of the adsorbates are revealed and explained in terms of strong and highly anisotropic electrostatic adsorbate-adsorbate interactions. The results are compared to published experimental and theoretical results, and differences in suggested binding geometries from the different studies are discussed. Dynamic properties of the adsorption, surface mobility, and surface reactivity are inferred from key elements of the potential energy surface obtained from the quantum chemical computations and supported by ab initio molecular dynamics simulations.