Formaldehyde adsorption geometry and energies over TiO2(1Â 1Â 0) rutile surface

- Two stable molecularly adsorbed modes of formaldehyde are observed on TiO2 (1 1 0).
- One perpendicular to the surface (1 1 0) plane and one tilted along the [11¯0] direction.
- The η1(O) tilt geometry is found to be more stable than the η1(O) straight geometry.
- For the tilted adsorption HOMO O2px, has considerable overlap with Ti 3d states.
- For the perpendicular adsorption HOMO-2, O 2pz, has the strongest overlap.