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New Theoretical Model Enhances Understanding of Multisite Alloy Catalysts
Two research teams have combined their expertise to introduce an innovative theoretical model aimed at characterizing the overall activity of multisite alloy catalysts. Their findings, which appear in the Journal of the American Chemical Society, revolve around a newly proposed concept known as the equivalent site ratio, which successfully quantifies the roles of different active sites found in Pt-Ru disordered solid solution (DSS) alloys.
These DSS alloys are notable for their plethora of catalytic sites, which render them effective for facilitating a variety of significant chemical reactions. However, evaluating their activity localization and overall performance has presented formidable challenges due to the extensive computational resources required for accurate assessments.
This necessity has led the researchers to develop a streamlined yet precise computational approach capable of efficiently describing the overall activity of these multi-site alloy catalysts, thus enabling the optimization of the proportions of alloying components.
To tackle this complex issue, the research teams utilized high-throughput computational techniques that incorporated density functional theory (DFT) and machine learning. This combination allowed them to generate comprehensive data regarding hydrogen adsorption free energy across multiple random sites within the Pt-Ru DSS alloy.
By analyzing both radial distribution and site energy distribution, they established a crucial link connecting the microstructure of active sites to their intrinsic catalytic activity. Their research identified the sites Pt3|Ru1 and Pt3|Ru3 as the most effective for the hydrogen evolution reaction (HER).
Furthermore, the introduction of the equivalent site proportion has unveiled a quantitative relationship that clarifies how the number of active sites correlates with intrinsic activity and overall catalyst performance. Their predictions indicate that the equivalent site proportion reaches its maximum at relatively low concentrations of Ru, while a notable increase in the activity of the Pt3|Ru1 and Pt3|Ru3 sites occurs with Ru content ranging from 20% to 30%. Follow-up experimental results aligning closely with these predictions affirm the reliability of their statistical methods and the innovative equivalent site proportion concept.
In previous research, the team had successfully employed statistical analysis to screen various multi-element two-dimensional layered materials for sulfur reduction reaction (SRR) catalysts, achieving a screening accuracy above 93% based on Gibbs free energy calculations for SRR candidates. This foundational work has bolstered their current investigation into DSS alloys.
This current study not only sheds light on the effects of multi-component systems and multisite interactions but also enhances the understanding of the reaction pathways for electrocatalysts. The methodologies developed through their work contribute significant advancements for high-throughput screening and the functional modulation of catalysts, paving the way for the design of more efficient and targeted catalytic systems.
The research was spearheaded by Professors Song Li and Wu Xiaojun from the National Synchrotron Radiation Laboratory at the University of Science and Technology of China (USTC), part of the Chinese Academy of Sciences (CAS).
More information: Quan Zhou et al, Analyzing the Active Site and Predicting the Overall Activity of Alloy Catalysts, Journal of the American Chemical Society (2024). DOI: 10.1021/jacs.4c01542
Citation: Theoretical model for multisite alloy catalyst design quantifies active site contributions (2024, September 9) retrieved 9 September 2024 from https://phys.org/news/2024-09-theoretical-multisite-alloy-catalyst-quantifies.html
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