Programme

O.10 -- Oral, VCTP-49

Date: Wednesday, 31 July 2024

Time: 17:20 - 17:45

Thermal stability of /Sr$_3$Ti$_2$O$_7$ catalyst under operando conditions revealed by machine learning enhanced global optimization

Thanh N. Pham(1), Beatriz A. C. Tan (1), Y. Hamamoto (1), K. Inagaki (1), I. Hamada (1), and Y. Morikawa (1)

(1) Departmentof Precision Engineering, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan Email: thanh@cp.prec.eng.osaka-u.ac.jp

Self-regenerative materials are pivotal for developing thermally-stable catalysts. Perovskite-supported metal nanoparticles (NPs) have shown promise. However, our understanding of the stability of perovskite-supported metal NPs remains limited. Herein, we elucidate the thermal stability of Pd/Sr$_3$Ti$_2$O$_7$ (STO-327) [1] by operando computer simulation that combines density functional theory (DFT) with machine learning-enhanced global optimization (GOFEE) [2] and thermodynamics [3]. First, we first elucidate the stability of Pd/STO-327 against the Pd dissolution deactivation by considering the thermodynamic phase diagram of Pd-doped STO-327. Second, we apply the GOFEE method based on an evolutionary algorithm and a Gaussian process regression, which is trained on the fly with DFT calculations, to the search for the stable structures of Pd$_x$O$_y$ on STO-327. We find that the formation of PdO-like clusters enhances their binding strength to the support, inhibiting the agglomeration (sintering) of the Pd$_x$O$_y$ NPs. By comparing with $\gamma$-Al$_2$O$_3$ supported Pd clusters, the interactions between Pd clusters and STO-327 surfaces are much stronger due to strong charge transfer interaction, highlighting that the Pd/STO-327 catalysts have a higher thermal stability. This work may provide a guideline for the rational design of the thermally stable catalyst against sintering. \\ [1] T. N. Pham, B. A. C. Tan, Y. Hamamoto, K. Inagaki, I. Hamada, Y. Morikawa, ACS Catal. 2024, 14, 1443. \\ [2] M. K. Bisho, B, Hammer, Phys. Rev. Lett. 2020, 124, 086102. \\ [3] K. Reuter, M. Scheffler, Phys. Rev. B 2001 65, 035406.

Presenter: Pham Ngoc Thanh