Journal
ACS CATALYSIS
Volume 5, Issue 12, Pages 7237-7243Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acscatal.5b01748
Keywords
water splitting density functional theory; DFT plus U; iron oxides; surface states
Categories
Funding
- Morantz Energy Research Fund
- Nancy and Stephen Grand Technion Energy Program
- I-CORE Program of the Planning and Budgeting Committee
- Israel Science Foundation [152/11]
- Irwin and Joan Jacobs graduate school scholarship
- Leonard and Diane Sherman Interdisciplinary Graduate School Fellowship for excellence
- Rieger Foundation, Marshal-Tulin fellowship
Ask authors/readers for more resources
Understanding the role of an overlayer material on a catalyst is crucial for improving catalytic activity. Iron(III) oxide (alpha-Fe2O3) is a widely studied catalyst commonly used for solar water splitting. Recently, the water splitting efficiency with alpha-Fe2O3 was enhanced by deposition of an alpha-Al2O3 overlayer. In order to understand the origin of this improvement, we perform first-principles calculations with density functional theory + U on the alpha-Fe2O3(0001) surface with an alpha-Al2O3 surface overlayer. We find catalysis is unfavorable directly over alpha-Al2O3 and rather takes place over a-Fe203 exposed areas. In agreement with experiment, we find that alpha-Al2O3 coverage decreases the overpotential required for water oxidation on alpha-Fe2O3. We explain this improvement through the decrease in the work function of alpha-Fe2O3 upon aAl(2)O(3) coverage that aids in extracting electrons during the water oxidation reaction. We suggest that selecting an overlayer with a smaller work function than that of the catalyst as a strategy for future development of better catalysts.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available