The impact of surface composition on Tafel kinetics leading to enhanced electrochemical insertion of hydrogen in palladium

Dmitriyeva, Olga; Hamm, Steven C.; Knies, D. L.; Cantwell, R.; McConnell, Matt

doi:10.1016/j.apsusc.2018.01.129

Cited by 5 publications

(3 citation statements)

References 31 publications

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“…Given the electrochemical conditions and low formate concentration in experiments, we assume that formate is produced by irreversible electrochemical reduction of the adsorbed CO 2 intermediate. Finally, we assume that hydrogen evolution only occurs via a combination of two hydrogen atoms (Tafel step), which is in agreement with the literature at a mild cathodic potential. − …”

Section: Resultssupporting

confidence: 87%

Mechanism and Micro Kinetic Model for Electroreduction of CO₂ on Pd/C: The Role of Different Palladium Hydride Phases

et al. 2021

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We measured the reaction kinetics of the electrochemical reduction of CO2 to formate on Pd/C and evaluated several proposed mechanisms, by comparing model-described and observed rates of formation of HCOO– and H2 as a function of several parameters (p H2 , p CO2 , and potential). An α-/β-hydride mechanism, based on an α-hydride phase active for CO2 reduction and a β-hydride Pd-phase active for hydrogen evolution, described the experimental data of our and other laboratories reported in the literature satisfactorily. After parametrization, using a data set including only H2, this mechanism also predicted the outcome of D2 isotope labeling experiments correctly. Analyses of the results indicate that the α-/β-hydride ratio and hydride formation rate are key factors affecting the formate production rate and the selectivity, thereby identifying areas for further (spectroscopic) studies and mechanism validation.

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Section: Resultssupporting

confidence: 87%

Mechanism and Micro Kinetic Model for Electroreduction of CO₂ on Pd/C: The Role of Different Palladium Hydride Phases

et al. 2021

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“…Increasing Pd’s surface-area-to-volume ratio by nanoscaling its dimensions is a promising route for overcoming this barrier. Indeed, nanoscopic Pd is an exceptional model metal hydride system that has enabled general insights into how physical properties like nanoparticle size, surface faceting, and surface chemistry influence hydrogen absorption (H abs ) and desorption (H des ) kinetics and thermodynamics in nanomaterials. − While parameters like particle size reduction, facet engineering, , grain engineering, alloying, , and surface modification ,− have all been successfully demonstrated to increase H abs/des rates in Pd, controlling kinetic pathways and their corresponding rate-determining steps remains a central challenge for accelerating H abs/des in Pd nanostructures.…”

Section: Introductionmentioning

confidence: 99%

“…Interestingly, whereas E A values for H des of gas-phase measurements are typically several times greater than E A for H abs ,46 our values are nearly equivalent. This is likely an effect of H des being controlled exclusively by Volmer kinetics (i.e., no hydrogen bond formation is required for electrochemical H des [Tafel/Heyrovsky step]) 27. Nevertheless, the nearly identical D eff values for Pd {100} and Pd@Pt {100}, combined with the dramatic decrease in E A with the addition of Pt to the Pd {100} surface, provide clear evidence that the nanocube surface controls the H abs/des kinetics in Pd nanocubes and can be easily modified.…”

mentioning

confidence: 99%

Accelerating Hydrogen Absorption and Desorption Rates in Palladium Nanocubes with an Ultrathin Surface Modification

et al. 2021

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Exploiting the high surface-area-to-volume ratio of nanomaterials to store energy in the form of electrochemical alloys is an exceptionally promising route for achieving high-rate energy storage and delivery. Nanoscale palladium hydride is an excellent model system for understanding how nanoscale-specific properties affect the absorption and desorption of energy carrying equivalents. Hydrogen absorption and desorption in shape-controlled Pd nanostructures does not occur uniformly across the entire nanoparticle surface. Instead, hydrogen absorption and desorption proceed selectively through high-activity sites at the corners and edges. Such a mechanism hinders the hydrogen absorption rates and greatly reduces the benefit of nanoscaling the dimensions of the palladium. To solve this, we modify the surface of palladium with an ultrathin platinum shell. This modification nearly removes the barrier for hydrogen absorption (89 kJ/mol without a Pt shell and 1.8 kJ/mol with a Pt shell) and enables diffusion through the entire Pd/Pt surface.

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Hydrogen Absorption in Palladium‐Based Nanocrystals for Electrocatalysis Investigation

Chen,

Hou,

Govor

et al. 2024

ChemElectroChem

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Hydrogen absorption in transition metals has received enormous attention for applications such as the hydrogen storage, sensing and corrosion. In particular, the Pd‐H system is a simple and classical metal hydride system that serves as a platform for a deeper understanding of hydrogen behavior. In the past few years, Pd‐H has been reported as electrocatalyst in multiple reactions, whereas the impact of hydrogen absorption/desorption in electrocatalytic applications remains unclear. Therefore, in this concept, factors influencing the hydrogen adsorption/desorption of palladium in the gas phase, such as facet engineering, ligand effects, and alloying effects, are summarized. Subsequently, in the context of electrocatalysis, factors affecting electrochemical hydrogen adsorption/desorption are outlined. Particularly, prospects for the further investigation of electrochemical hydrogen adsorption/desorption in catalysis are discussed.

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The impact of surface composition on Tafel kinetics leading to enhanced electrochemical insertion of hydrogen in palladium

Cited by 5 publications

References 31 publications

Mechanism and Micro Kinetic Model for Electroreduction of CO₂ on Pd/C: The Role of Different Palladium Hydride Phases

Mechanism and Micro Kinetic Model for Electroreduction of CO₂ on Pd/C: The Role of Different Palladium Hydride Phases

Accelerating Hydrogen Absorption and Desorption Rates in Palladium Nanocubes with an Ultrathin Surface Modification

Hydrogen Absorption in Palladium‐Based Nanocrystals for Electrocatalysis Investigation

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The impact of surface composition on Tafel kinetics leading to enhanced electrochemical insertion of hydrogen in palladium

Cited by 5 publications

References 31 publications

Mechanism and Micro Kinetic Model for Electroreduction of CO2 on Pd/C: The Role of Different Palladium Hydride Phases

Mechanism and Micro Kinetic Model for Electroreduction of CO2 on Pd/C: The Role of Different Palladium Hydride Phases

Accelerating Hydrogen Absorption and Desorption Rates in Palladium Nanocubes with an Ultrathin Surface Modification

Hydrogen Absorption in Palladium‐Based Nanocrystals for Electrocatalysis Investigation

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Product

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Mechanism and Micro Kinetic Model for Electroreduction of CO₂ on Pd/C: The Role of Different Palladium Hydride Phases

Mechanism and Micro Kinetic Model for Electroreduction of CO₂ on Pd/C: The Role of Different Palladium Hydride Phases