Bridging the Gap between the X-ray Absorption Spectroscopy and the Computational Catalysis Communities in Heterogeneous Catalysis: A Perspective on the Current and Future Research Directions

Abstract

X-ray absorption spectroscopy (XAS) [extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES)] is a key technique within the heterogeneous catalysis community to probe the structure and properties of the active site(s) for a diverse range of catalytic materials. However, the interpretation of the raw experimental data to derive an atomistic picture of the catalyst requires modeling and analysis; the EXAFS data are compared to a model, and a goodness of fit parameter is used to judge the best fit. This EXAFS modeling can often be nontrivial and time-consuming; overcoming or improving these limitations remains a central challenge for the community. Considering these limitations, this Perspective highlights how recent developments in analysis software, increased availability of reliable computational models, and application of data science tools can be used to improve the speed, accuracy, and reliability of EXAFS interpretation. In particular, we emphasize the advantages of combining theory and EXAFS as a unified technique that should be treated as a standard (when applicable) to identify catalytic sites and not two separate complementary methods. Building on the recent trends in the computational catalysis community, we also present a community-driven approach to adopt FAIR Guiding Principles for the collection, analysis, dissemination, and storage of XAS data. Written with both the experimental and theory audience in mind, we provide a unified roadmap to foster collaborations between the two communities.

Challenges and Opportunities in Engineering the Electronic Structure of Single-Atom Catalysts

“… ,, Aiming to gain atomistic insights into the active site structure, theoretical simulations often further integrate these experimental techniques by predicting the thermodynamic stability of metal species in different potential oxidation and coordination environments (Figure ). Furthermore, computational studies typically aim to identify key electronic parameters for catalytic behavior rationalization by evaluation of adsorbate binding energies. , However, SACs often present unique electronic features (vide supra), invalidating well-established catalytic descriptors (i.e., the d -band center) in extended metal surfaces. Unfolding the complex electronic structure of SACs and how the latter impacts the metal atom reactivity are nontrivial tasks that require a multitechnique approach.…”

Studying, Promoting, Exploiting, and Predicting Catalyst Dynamics: the Next Frontier in Heterogeneous Catalysis

“…One other set of catalyst dynamic behavior that has recently received attention is the concept of dynamic fluxionality. , Fluxionality in catalysis mainly describes subnano metallic clusters that exhibit structural flexibility due to their delocalized, unsaturated bonds. These metallic clusters are easily perturbed under reaction conditions and can have hundreds of metastable configurations.…”

Dual Atom Catalysts for Energy and Environmental Applications

“…We highlight that the optimal case for using XAS to characterize DACs is when dinuclear sites are dominating. It might be dangerous to use XAS for catalyst with less uniform dimeric active sites given the complexity of the material [50] . XAS collects sample‐averaged information and the contribution from other species (e.g., single atoms and clusters) need to be carefully considered [33] …”