Effect of spin contamination error on surface catalytic reaction: NO reduction by core-shell catalysts

ABSTRACT

The effects of spin contamination errors on the activation barriers of catalytic NO reduction by TiO₂/Ag and ZrO₂/Cu core-shell catalyst models were investigated using an approximate spin projection method and an unrestricted density functional theory calculation with the plane-wave basis set. The estimated barrier of the TiO₂/Ag system increased (0.03 eV), whereas that of the ZrO₂/Cu system decreased (0.04 eV) after the correction of the spin contamination error. This difference in the estimated barriers of the two systems can be attributed to the difference in their surface structures. The error obtained for the TiO₂/Ag system was larger than that obtained for the gas phase, i.e. the spin contamination error was induced by the molecule/surface interaction. Moreover, the error correction also changed the rate-determining step of ZrO₂/Cu. These results demonstrate the importance of the correction of spin contamination errors for the detailed investigation of catalytic reactions.

GRAPHICAL ABSTRACT

KEYWORDS:

• Spin contamination error
• approximate spin projection method
• NO_x reduction
• TiO₂/Ag
• ZrO₂/Cu

Acknowledgements

This work was conducted under the management of the ‘Elements Strategy Initiative for Catalysts and Batteries (ESICB)’ supported by the Ministry of Education, Culture, Sports, Science, and Technology, Japan. The authors would like to thank Editage (www.editage.jp) for the English language editing.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by JSPS KAKENHI [grant number 17H07396].