Abstract
A previous study showed that TiO 2-B (100) surface is very unique. It is characterised by high activity and a loose structure. In this study, we studied the adsorption of ammonia on TiO 2-B (100) surface at coverages ranging from 1/6 ML to 1 ML using ab initio density functional calculations. We also investigated the adsorption of an isolated ammonia molecule on TiO 2-B (001) surface to compare the different activities of TiO 2-B (100) and (001) surfaces towards NH 3. The results showed that the TiO 2-B (100) surface is more reactive towards NH 3 molecule than TiO 2-B (001) surface, and the Lewis acid site on TiO 2-B (100) surface is more acidic. The decrease rate of the average molecular adsorption energy of NH 3 with coverage on TiO 2-B (100) surface is substantially lower than that on a rutile (011) surface above 1/2 ML coverage due to the open structure of TiO 2-B (100) surface. The average molecular adsorption energy shows a linear dependence on the coverage of y = 111.0 - 36.3x on TiO 2-B (100) surface. The possibility of NH 3 molecule onto the Ti 5c site is nearly equal to forming a dimer with adsorbed NH 3 on TiO 2-B (100) surface at 5/6 ML coverage.
| Original language | English |
|---|---|
| Pages (from-to) | 16618-16625 |
| Number of pages | 8 |
| Journal | Physical Chemistry Chemical Physics |
| Volume | 14 |
| Issue number | 48 |
| DOIs | |
| State | Published - 28 Dec 2012 |