| Description: | [DCS seminar] Seenivasan, H and Tiwari, A. K (IISER Kolkata) -- Water dissociation on nickel surfaces: Effect of surface temperature on reactivity |
| Date: | Wednesday, Aug 26, 2015 |
| Time: | 4 p.m. - 5 p.m. |
| Venue: | G08, Lecture Hall Complex |
| Details: | Water adsorption and dissociation is the rate limiting step in the industrially important water gas-shift reaction. Quantum dynamics studies of H2O dissociation on static Cu(111) surfaces found that vibrational excitation promotes dissociation [1,2]. But, previous studies on CH4 and H2 indicated that the dissociation probability strongly depends on the surface temperature [3-5]. So, the effect surface temperature on adsorption and dissociation of water on low index (111), (110) and (100) surfaces of nickel influenced by the lattice motion was studied in detail using ‘sudden approximation’ [4]. Water adsorbed on top site on all surfaces while adsorption was stronger on the Ni(110) surface. Dissociation barrier was low on Ni(110) compared to Ni(100) and Ni(111). Significant shift of barrier energies and dissociation probabilities to lower incidence energies with surface temperature is observed for water on the nickel surfaces [6]. Motion of the second layer atoms were found to be important on Ni(110) surface. Recent combined experimental and theoretical study on D2O on Ni(111) incorporating lattice motion corroborates with our observation [7]. Keywords: Water dissociation; Nickel surfaces; Surface temperature; Lattice motion; Sudden approximation. |
| Calendar: | Seminar Calendar (entered by arun.ds) |