Publications

Calcium Doping Facilitates Water Dissociation in Magnesium Oxide

Author(s)
Danny Müller, Christian Knoll, Thomas Ruh, Werner Artner, Jan M. Welch, Herwig Peterlik, Elisabeth Eitenberger, Gernot Friedbacher, Michael Harasek, Peter Blaha, Klaudia Hradil, Andreas Werner, Peter Weinberger
Abstract

Calcium doping of magnesium oxide results in significantly increased water dissociation rates, thus enhancing both hydration rate and reaction completeness of hydration compared to pure MgO. For a series of mixed magnesium-calcium oxides (MgxCa1-xO) with varying Ca contents between 0% and 40%, the material of a composition Mg0.9Ca0.1O shows the fastest rehydration, transforming completely within 80 min to the mixed hydroxide. In consecutive dehydration/rehydration cycles, reasonable cycle stability is found. A "regeneration" of the aged material (reactivity reduced by excessive cycling) in liquid water re-establishes the initial rehydration reactivity. Density functional theory calculations support the experimental findings, confirming that calcium doping can reduce the energy of the rate limiting water dissociation reaction, exploiting both electronic and steric (size) effects.

Organisation(s)
Dynamics of Condensed Systems
External organisation(s)
Technische Universität Wien
Journal
Advanced Sustainable Systems
Volume
2
No. of pages
6
ISSN
2366-7486
DOI
https://doi.org/10.1002/adsu.201700096
Publication date
01-2018
Peer reviewed
Yes
Austrian Fields of Science 2012
103015 Condensed matter, 103018 Materials physics, 103009 Solid state physics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/calcium-doping-facilitates-water-dissociation-in-magnesium-oxide(8c9bd6a1-d2e7-4ff0-a811-925b68d55f62).html