Understanding Synthesis and Structural Variation of Nanomaterials Through In Situ/Operando XAS and SAXS

Fang, Lingzhe; Seifert, Söenke; Winans, Randall E.; Li, Tao

doi:10.1002/smll.202106017

Cited by 34 publications

(29 citation statements)

References 72 publications

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“…With an increasing demand for real-time detection of catalysts during reaction processes, various in situ characterizations have been developed, which seem to be excellent solutions to this problem. [198][199][200][201][202][203] In situ X-ray spectroscopy can detect the active phase transition, electronic oxidation/spin state, electronic structure, and local environment of catalysts, [204][205][206][207] and in situ vibrational spectroscopy can monitor the structural evolution of catalysts and the composition of intermediates during the catalytic process. [208,209] All of the above information can be predicted by theoretical calculations and simulations while demonstrated by in situ characterizations.…”

Section: Combination With Advanced In Situ Characterizationsmentioning

confidence: 99%

Advancing the Electrochemistry of Gas‐Involved Reactions through Theoretical Calculations and Simulations from Microscopic to Macroscopic

Liu

Wang

et al. 2022

Adv Funct Materials

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Nowadays, gas‐involved electrochemical reactions, such as carbon dioxide reduction reaction (CO2RR), nitrogen reduction reaction (NRR), and hydrogen evolution reaction (HER), have gradually become viable solutions to the global environmental pollution and energy crisis. However, their further development is inseparable from the in‐depth understanding of reaction mechanisms, which are incredibly complicated and cannot be satisfied by experiments alone. In this context, theoretical calculations and simulations are of great significance in establishing composition–structure–activity relationships, providing priceless mechanistic discernment and predicting prospective electrocatalysts and systems. Among them, density functional theory (DFT), molecular dynamics (MD) simulations, and finite element simulation (FES) are emerging as three mature theoretical tools. This paper presents a review of the basic principles and research progress of DFT, MD, and FES to deepen the understanding of CO2RR, NRR, and HER. Some remarkable work around theoretical calculations and simulations are highlighted, including the utilization of DFT to investigate the intrinsic properties of catalysts and MD or FES to restore the whole reaction systems from different temporal and spatial scales. Eventually, to sum up, forward‐looking insights and perspectives on the future optimizations and application modes of the three computational techniques to compensate for their shortcomings and limitations are presented.

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Section: Combination With Advanced In Situ Characterizationsmentioning

confidence: 99%

Advancing the Electrochemistry of Gas‐Involved Reactions through Theoretical Calculations and Simulations from Microscopic to Macroscopic

Liu

Wang

et al. 2022

Adv Funct Materials

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“…XAS (also name as X-ray absorption fine structure, XAFS), is a form of inelastic scattering, including X-ray absorption near-edge structure (XANES) (with a region up to ~ 25 eV above the edge), and extended X-ray absorption fine structure (EXAFS) (with a region of higher energies) [48,79]. The former (XANES) can reveal the oxidation state and electronic configuration information.…”

Section: In-situ X-ray Absorption Spectroscopy (Xas)mentioning

confidence: 99%

“…Thus, the development of in-situ characterization techniques to monitor the catalyst structure evolution in real time is essential to determine the active sites, which can also reveal the rationality of the catalyst structure design and guide the synthesis of the highly active catalyst. In addition, despite a rational design of the catalyst with the highly active sites being crucial for efficient ORR, the reactions that occur during synthesis are not known, leading to a complex synthesis process, and exacerbating costs [48,49]. Thus, the visual monitoring of the structural morphological changes, including nucleation, growth, reconstruction, Ostwald ripening, etc., for the catalyst during the synthesis process is also essential to simplify the synthesis process and shorten the synthesis time, which cannot be ignored.…”

Section: Introductionmentioning

confidence: 99%

“…As well as, the postprocess nature of common ex-situ characterization techniques limit the recognition of their true changes in real time. Hence, the exploitation of in-situ characterization techniques to accurately determine the evolutionary behavior of the intermediates (adsorption/desorption) or products (such as nucleation, growth, and reconstruction) is very necessary and should be equally emphasized [48]. Expressly, in-situ techniques can reveal their dynamic changes during the reaction and do not require the dismantling of the test cell, thus obtaining more valuable information to reversely clarify the active site and intuitively elucidate the ORR mechanism [55][56][57].…”

Section: Introductionmentioning

confidence: 99%

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A Review of In-Situ Techniques for Probing Active Sites and Mechanisms of Electrocatalytic Oxygen Reduction Reactions

et al. 2022

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Electrocatalytic oxygen reduction reaction (ORR) is one of the most important reactions in electrochemical energy technologies such as fuel cells and metal–O2/air batteries, etc. However, the essential catalysts to overcome its slow reaction kinetic always undergo a complex dynamic evolution in the actual catalytic process, and the concomitant intermediates and catalytic products also occur continuous conversion and reconstruction. This makes them difficult to be accurately captured, making the identification of ORR active sites and the elucidation of ORR mechanisms difficult. Thus, it is necessary to use extensive in-situ characterization techniques to proceed the real-time monitoring of the catalyst structure and the evolution state of intermediates and products during ORR. This work reviews the major advances in the use of various in-situ techniques to characterize the catalytic processes of various catalysts. Specifically, the catalyst structure evolutions revealed directly by in-situ techniques are systematically summarized, such as phase, valence, electronic transfer, coordination, and spin states varies. In-situ revelation of intermediate adsorption/desorption behavior, and the real-time monitoring of the product nucleation, growth, and reconstruction evolution are equally emphasized in the discussion. Other interference factors, as well as in-situ signal assignment with the aid of theoretical calculations, are also covered. Finally, some major challenges and prospects of in-situ techniques for future catalysts research in the ORR process are proposed.

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“…Wei et al used EXAFS in combination with other spectroscopic and imaging techniques to observe the transition of noble metal nanoparticles (Pt, Pd, and Au–NPs) to thermally stable single atom catalyst when calcined above 900 °C under inert conditions . Similarly, review articles focused on atomically dispersed catalysts frequently highlight the significance of EXAFS in understanding the local structure of the active species, thus reemphasizing the relevance of using theory to model EXAFS data. ,− …”

Section: How Is Exafs Being Currently Used By the Catalysis Science C...mentioning

confidence: 99%

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

et al. 2022

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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.

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Understanding Synthesis and Structural Variation of Nanomaterials Through In Situ/Operando XAS and SAXS

Cited by 34 publications

References 72 publications

Advancing the Electrochemistry of Gas‐Involved Reactions through Theoretical Calculations and Simulations from Microscopic to Macroscopic

Advancing the Electrochemistry of Gas‐Involved Reactions through Theoretical Calculations and Simulations from Microscopic to Macroscopic

A Review of In-Situ Techniques for Probing Active Sites and Mechanisms of Electrocatalytic Oxygen Reduction Reactions

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

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