Understanding trends in the mercury oxidation activity of single-atom catalysts

Yang, Weijie; Chen, Xuelu; Feng, Yanbin; Wang, Fei; Gao, Zhengyang; Liu, Yanfeng; Ding, Xun‐Lei; Li, Hao

doi:10.1039/d2en00286h

Cited by 18 publications

(8 citation statements)

References 65 publications

(73 reference statements)

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“…Yang et al 11,12 used a combined theoretical and experimental method to analyze the reaction mechanism of Fe SACs for the catalytic Hg 0 oxidation using O 2 ; they found that Fe SA /DV-N 4 has the highest catalytic activity, with an RDS energy barrier of 2.34 eV. Our previous study 13 predicted the catalytic activity of 3d, 4d, and 5d metal SACs (in the form of metal 1 −N 4 −C) for catalytic Hg 0 oxidation by the derived volcano activity plots; the results showed that Fe 1 −N 4 −C has the highest catalytic activity. However, it was found that the SACs catalyzed Hg 0 oxidations generally have high RDS energy barriers (>2 eV).…”

Section: Introductionmentioning

confidence: 99%

Design of Single-Atom Catalysts for Hg⁰ Oxidation Using H₂O₂

Yang

Chen

et al. 2022

J. Phys. Chem. C

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Hg0 removal is the most difficult part in mercury purification due to its insolubility in water and strong volatility. Catalytic oxidation is the main method for Hg0 removal. O2 and hydrogen halides (HCl and H2S) are common oxidants for catalytic Hg0 oxidation. However, previous studies showed that current catalytic oxidation routes have sluggish kinetics and may cause secondary pollution. Herein, we propose a new pathway for catalytic Hg0 oxidation on the surface of single-atom catalysts (SACs) using the green oxidant H2O2. Some potential catalysts were screened by analyzing the adsorption and activation mechanism of H2O2 on the surface of SACs. Spin-polarized density functional theory calculations with van der Waals corrections (DFT-D3) revealed that Zn1–N4–C has the lowest rate-determining step barrier (0.35 eV) among the analyzed systems. This study proposes a promising pathway for a kinetically facile catalytic Hg0 oxidation, providing a new option for effective Hg0 removal.

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Section: Introductionmentioning

confidence: 99%

Design of Single-Atom Catalysts for Hg⁰ Oxidation Using H₂O₂

Yang

Chen

et al. 2022

J. Phys. Chem. C

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“…Using the same modeling method as refs, ,, microkinetic modeling based on the previously mentioned kinetic parameters was carried out to further assess the catalyst activity in flue gas conditions. Herein, we selected temperature ( T ) and pressure ( P ) as the two descriptors and [log(TOF)] as the reaction evaluator (Figure ).…”

Section: Resultsmentioning

confidence: 99%

“…In this work, the process of oxidizing NO using H 2 O 2 over Fe–N 4 –C was studied by spin-polarized DFT calculations (ISPIN=2 of the VASP INCAR) with van der Waals corrections (DFT-D3). The reason for choosing Fe–N 4 –C as an example is that it is proven highly effective for both NO and Hg 0 oxidation using O 2 as the oxidant and can reach the theoretical optimal activity compared to other SACs. , First, we analyzed the adsorption properties of the *OH, *O, and *OOH species generated by *H 2 O 2 activation and other gas molecules (e.g., *NO) on the catalyst surface. After that, the catalytic oxidation of NO by *OH, *O, and *OOH on Fe–N 4 –C reaction pathways were thoroughly examined.…”

Section: Introductionmentioning

confidence: 99%

“…Catalytic oxidation is currently observed as the emerging roadmap for multipollutant removal in coke-fired flue fumes. , Among the advanced oxidation processes, it has drawn more attention due to its effectiveness in waste removal, low cost, low levels of secondary pollution, and the ability to recycle reaction products. Hydrogen peroxide (H 2 O 2 ), one of the 100 most important chemicals in the world, is often used as an oxidant, disinfectant, and bleach in chemical industries. , The energy required for NO to be oxidized by H 2 O 2 was determined by Wen et al after studying the de-oxidation of NO with H 2 O 2 urea solution.…”

Section: Introductionmentioning

confidence: 99%

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NO Oxidation Using H₂O₂ at a Single-Atom Iron Catalyst

et al. 2023

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Nitrogen oxide (NO) is a major worldwide environmental pollutant, which can be eliminated effectively by catalytic oxidation. However, conventional catalysts generally suffer from poor activity and low oxidation rates, limiting the development of gas pollutant removal. To overcome this issue, the high activity of a single-atom catalyst and the strong oxidizability of H2O2 are proposed for the catalytic oxidation of NO in this work. Herein, the 14 reaction pathways of NO oxidation using H2O2 were obtained through spin-polarized density functional theory calculation with van der Waals corrections and microkinetic modeling. Considering the possible H2O2 activation products of *OH, *OOH, and *O, we obtained the dominant reaction pathways for different oxidizing species: (i) Langmuir–Hinshelwood mechanism of *OH (mainly forming *HNO2), (ii) Eley–Rideal mechanism of *O (forming *NO2), and (iii) *OOH (forming *HNO3), with the energy barriers of 0.94, 1.42, and 0.14 eV, respectively. Among the three reaction patterns, NO oxidation using *OOH is the most favorable, with the highest reaction rate. *HNO3 is the most likely oxidation product of NO oxidation using H2O2. Meanwhile, it is notable that the *OH catalytic oxidation of NO has multiple reaction pathways and products, including HNO2, NO2, and HNO3. Compared to the use of conventional oxidants and catalysts, using H2O2 to oxidize NO at Fe–N4–C catalyst has lower reaction energy barriers and allows for the deep oxidation of NO. This study illustrates the reaction pathway of NO oxidation using H2O2 and demonstrates that it is theoretically feasible, which provides guidance for the subsequent preparation of the material.

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“…Based on the seminal Sabatier principle, a good heterogeneous catalyst should neither bond to the adsorbate too strongly nor too weakly [110]. Therefore, almost all the derived heterogeneous catalytic models present a "volcano-shape" as a function of the key adsorbate binding energies (i.e., adsorption energies) of the reaction [111][112][113][114][115][116][117][118][119][120][121][122][123]. A catalytic volcano model allows people to derive the optimal activity of catalysis.…”

Section: Catalyst Design To Improve Activity and Target-product Selec...mentioning

confidence: 99%