Abstract
A general stoichiometric cation exchange mechanism does not fully explain the unique exchange behaviors of Na-4-mica, the most highly charged swelling 2:1 phyllosilicate. Herein, we present for the first time a novel model of hydronium-promoted equilibrium for the cation exchange reaction of highly charged swelling 2:1 phyllosilicates with alkali metal cations. The exchange reaction of Na-4-mica with alkali metal cations revealed that adsorbed cations undergo further exchange with hydronium ions to result in the unprecedented back-release and position rearrangement of adsorbed cations. During the exchange reaction, hydronium ions play a key role as not competitive but stabilizing cation. Stabilization is accomplished through replacing half of the adsorbed cations and consequently relocating their position. Therefore, this hydronium-promoted equilibrium mechanism would provide a novel intellectual framework not only for understanding cation exchange reactions of various highly charged phyllosilicates but also for exploring their potential for new applications.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 18678-18683 |
| Number of pages | 6 |
| Journal | Journal of Physical Chemistry C |
| Volume | 116 |
| Issue number | 35 |
| DOIs | |
| State | Published - Sep 6 2012 |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- General Energy
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films