Partially hydroxylated polycrystalline ionic oxides: a new route toward electron-rich surfaces |
| |
Authors: | Napoli Francesco Chiesa Mario Giamello Elio Finazzi Emanuele Valentin Cristiana Di Pacchioni Gianfranco |
| |
Institution: | Dipartimento di Chimica IFM and NIS Centre of Excellence, Università di Torino, Via P. Giuria, 7-10125, Torino, Italy. |
| |
Abstract: | Charge traps at the surface of oxide materials play a fundamental role in various chemical processes, such as the activation of supported metal clusters. In this study, combining electron paramagnetic resonance with cluster model DFT calculations, we show that excess electrons at the surface of MgO, CaO, and SrO polycrystalline materials can be generated by preparing weakly hydroxylated surfaces followed by deposition of small amounts of alkali metals. The residual OH groups present on specific sites of the partially dehydroxylated surface act as stable traps for electrons donated by the alkali metal (Na in this case) which forms a Na+ ion distant from the trapped electron. This process results in the formation of thermally stable (H+)(e-) color centers at the surface of the oxide. The procedure could be of interest for the stabilization and activation of supported metal nanoparticles with potential use in catalysis. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|