Coverage-dependent thermodynamic analysis of the formation of water and hydrogen peroxide on a platinum model catalyst

Morais, Rodrigo Ferreira de; Franco, Alejandro A.; Sautet, Philippe; Loffreda, David

doi:10.1039/c4cp03755c

Cited by 20 publications

(21 citation statements)

References 82 publications

(241 reference statements)

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“…Apart from the 4 e – reduction of oxygen to form H 2 O (eq 6), oxygen reduction can also proceed through the 2e – pathway in which the intermediate OOH* reduces to hydrogen peroxide (H 2 O 2 ) . Hydrogen peroxide (H 2 O 2 ), though undesirable in a fuel cell, is a strong and environmentally benign oxidizing agent. , Therefore, understanding the selectivity of the 2e – and the 4 e – ORR is beneficial. − The associate 2 e – ORR can be written as follows: The adsorption energies of the intermediate OOH* calculated in the 4e – ORR model could be directly used to understand the 2e – oxygen reduction to hydrogen peroxide (H 2 O 2 ).…”

Section: Resultsmentioning

confidence: 99%

Quantifying Uncertainty in Activity Volcano Relationships for Oxygen Reduction Reaction

2016

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The oxygen reduction reaction (ORR) is an important electrochemical reaction and a major bottleneck for fuel cells. Due to the existence of a scaling relation between the adsorption energies of two key intermediates involved in ORR, OOH*, and OH*, the electrocatalytic activity for the ORR, to a first approximation, is determined by a single descriptor. This descriptor-based approach has been used to screen for electrocatalyst materials that have an optimal binding energy of oxygen intermediates. However, given that this descriptor-based search relies on several approximations, it is crucial to determine the overall predictability of the descriptor-based model to determine the activity of a catalyst. In this work, we develop a formalism for estimating uncertainty for the activity of a catalyst in an electrocatalytic reaction scheme and apply this framework to determine errors involved in describing the ORR activity. We perform density functional theory calculations using the Bayesian Error Estimation Functional with van der Waals exchange–correlation functional to determine the adsorption energies of ORR intermediates on transition-metal fcc(111) and fcc(100) facets. We show that the error estimates for the adsorption energies calculated with a reference metal surface, chosen here to be Pt(111), are much smaller than those calculated with gas-phase molecules as reference. We demonstrate that ΔG OH and ΔG OOH are the optimal descriptors for the 4e– and the 2e– ORR, respectively. We show that for the 4e– ORR with ΔG OH as the descriptor, the uncertainty in activity is determined by the error associated with the adsorption energy of OH* (∼0.1 eV) for materials that lie on the strong binding leg, and the error involved in the scaling relation between OOH* and OH* (∼0.2 eV) determines the uncertainty in activity for the weak binding leg. We propose a parameter, the expected limiting potential, U EL, which is the expected value of U L. The deviation of the expected limiting potential, U EL, from the thermodynamic limiting potential, U L, provides a qualitative estimate of the prediction error and can be used to identify trends in predictability. We believe that the concept of the expected limiting potential will be crucial in descriptor-based screening studies for multielectron electrochemical reactions.

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Section: Resultsmentioning

confidence: 99%

Quantifying Uncertainty in Activity Volcano Relationships for Oxygen Reduction Reaction

2016

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“…In HSABs, ORR is a process of oxygen adsorption and catalytical reaction. A full reduction is a dissociative adsorption process, which begins with O2 adsorption on a catalyst surface [44,45]. The detailed ORR mechanism ( Fig.…”

Section: Electrochemical Reactions In Hsabmentioning

confidence: 99%

Recent advances in hybrid sodium–air batteries

Hui

Dinh

et al. 2019

Mater. Horiz.

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Hybrid sodium–air battery (HSAB) principles are introduced, and the synthesis and rational designs of electrocatalysts based on the oxygen reduction reaction/oxygen evolution reaction are comprehensively reviewed for the purpose of providing insight into the development of efficient air electrodes. Furthermore, research directions of anodes, electrolytes, and air electrodes toward high-performance HSABs are proposed.

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“…Classical microkinetic models were grounded on mean-field theory. It was found that the coverage effect plays a vital role in determining the reaction mechanism in our previous works. − , Models that do not consider the coverage effect may fail to explain the reaction mechanisms found in experiments. ,− , Undeniably, a deeper mechanism investigation on the direct synthesis of H 2 O 2 , including coverage effects, needs to be performed to accomplish a substantial breakthrough for this system. ,,, …”

Section: Introductionmentioning

confidence: 99%

“…57,[68][69][70]80 Undeniably, a deeper mechanism investigation on the direct synthesis of H 2 O 2 , including coverage effects, needs to be performed to accomplish a substantial breakthrough for this system. 27,31,65,66 In this work, we carry out the first detailed investigation of the reaction mechanisms for the direct synthesis of H 2 O 2 using the DFT-D3 functional and state-of-the-art microkinetic modeling 70,72 on three pure metal surfaces (Pd(111), Au(111), and Cu(111)) and two typical alloyed Pd surfaces (PdHg and PdAu). To be closer to the realistic conditions, the most challenging factor, lateral interactions (coverage effects) in kinetic modeling are explicitly taken into account.…”

Section: Introductionmentioning

confidence: 99%

“…Another vital operando spectroscopy by Selinsek et al indicated that the yield of H 2 O 2 was very small in both hydrogen-lean and hydrogen-rich conditions, with the selectivity being highly dependent on the composition of the environmental atmosphere (H 2 and O 2 ) . So far, the major setback for the further development of this system is the lack of understanding of the coverage effect on the direct synthesis of H 2 O 2 ; more connections between experiment and theory should be desirable. ,,,− …”

Section: Introductionmentioning

confidence: 99%

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Quantitative Insights into the Reaction Mechanism for the Direct Synthesis of H₂O₂over Transition Metals: Coverage-Dependent Microkinetic Modeling

et al. 2021

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The direct synthesis is the most promising alternative method for the production of hydrogen peroxide, and the bottleneck is still unsolved. The breakthrough lies in elusive reaction mechanism issues. In this work, advanced coverage-dependent kinetic modeling is combined with the energetics from firstprinciples calculations to investigate the formation of H 2 O 2 over transition metals. We show that the adsorbate−adsorbate interactions considerably affect the reaction mechanism of synthesis of hydrogen peroxide on Pd(111). Without the coverage effect, O 2 is likely to go through the direct dissociation mechanism, and water is the major product. When the coverage effects are included, the dissociations of O−O and O−OH bonds are significantly inhibited, and on the contrary, the hydrogenations of O 2 and OOH are promoted, leading to the production of H 2 O 2 . We demonstrate that the reaction temperature induces strong variations in the coverage of intermediates, which in turn causes changes in product selectivity. Being consistent with the operando experiment, our kinetic simulations indicate that the H 2 /O 2 partial pressure ratio has great effects on H 2 O 2 selectivity and the reaction rate of H 2 O 2 is lower under hydrogen-rich (oxygen-lean) and oxygen-rich (hydrogen-lean) conditions, which is highly related to the intermediate coverage. The same approach is also applied to other important relevant metals, i.e., Cu(111), Au(111), PdAu, and PdHg alloys, and the trends of activity and selectivity have been obtained.

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Coverage-dependent thermodynamic analysis of the formation of water and hydrogen peroxide on a platinum model catalyst

Cited by 20 publications

References 82 publications

Quantifying Uncertainty in Activity Volcano Relationships for Oxygen Reduction Reaction

Quantifying Uncertainty in Activity Volcano Relationships for Oxygen Reduction Reaction

Recent advances in hybrid sodium–air batteries

Quantitative Insights into the Reaction Mechanism for the Direct Synthesis of H₂O₂over Transition Metals: Coverage-Dependent Microkinetic Modeling

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Coverage-dependent thermodynamic analysis of the formation of water and hydrogen peroxide on a platinum model catalyst

Cited by 20 publications

References 82 publications

Quantifying Uncertainty in Activity Volcano Relationships for Oxygen Reduction Reaction

Quantifying Uncertainty in Activity Volcano Relationships for Oxygen Reduction Reaction

Recent advances in hybrid sodium–air batteries

Quantitative Insights into the Reaction Mechanism for the Direct Synthesis of H2O2over Transition Metals: Coverage-Dependent Microkinetic Modeling

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Product

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Quantitative Insights into the Reaction Mechanism for the Direct Synthesis of H₂O₂over Transition Metals: Coverage-Dependent Microkinetic Modeling