Ng, M.-F., Blackwood, D. J., Jin, H., Tan, T. L. Tuning oxygen reduction activity on chromia surface via alloying: a DFT study. Chem. Asian J., https://doi.org/10.1002/asia.202000997
Abstract:
Economical electro-catalysts for the oxygen reduction reaction (ORR) are highly desirable for a range of advance energy storage technologies. Chromium compounds have been suggested as one possible source of non-precious metal based catalysts for oxygen reduction reaction (ORR), especially chromia (Cr2O3) which is the most stable form of Cr oxide at room temperature. Using density functional theory + U calculations, we investigate the 4-electron ORR on the hydroxylated Cr2O3 surfaces alloyed with 17 different transition metals. On the one hand, we find that the ORR overpotential is lower when the Cr2O3 surface alloyed with elements towards the end of both the first and second rows of transition metals. Among these elements, Cd alloyed Cr2O3 surface is found to promote the ORR the most, but due to its high toxicity and price it loses out to Zn as the recommended alloyant. On the other hand, we find that the ORR overpotential is generally higher and less varied on the Cr2O3 surface alloyed with the early-to-mid row transition metal elements (e.g. Zr, Ti). As Cr2O3 is also a major component in the passive film on stainless steels, where a low ORR rate is desirable to reduce the impact of localized corrosion. This implies that alloying with early-to-mid row transition elements could be beneficial to stainless steels. The difference in oxygen reduction activity is attributed to the tendency of forming stable ORR intermediates during the oxygen reduction process.
License type:
Publisher Copyright
Funding Info:
This research / project is supported by the A*STAR - Structural Metal Alloys Programme
Grant Reference no. : A18B1b0061
Description:
This is the peer reviewed version of the following article: Ng, M.-F., Blackwood, D. J., Jin, H., Tan, T. L. Tuning oxygen reduction activity on chromia surface via alloying: a DFT study. Chem. Asian J., which has been published in final form at https://doi.org/10.1002/asia.202000997. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited