Surface properties of platinum and palladium

Galeev, T. K.; Bulgakov, N. N.; Savelieva, G. A.; Попова, Н. М.

doi:10.1007/bf02061265

Cited by 18 publications

(12 citation statements)

References 2 publications

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“…With increasing particle size, the relevance of surface tension effects [31][32][33]37] rises, which particularly influences the Pt-Pd alloy. Moreover, compared to metallic Pt, Galeev et al [53] report a lower surface energy for metallic palladium. Such energy differences result in a different stability of the noble metal phases and can ultimately promote a separation of palladium and platinum.…”

Section: Discussionmentioning

confidence: 99%

Effects of Hydrothermal Aging on CO and NO Oxidation Activity over Monometallic and Bimetallic Pt-Pd Catalysts

et al. 2021

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By combining scanning transmission electron microscopy, CO chemisorption, and energy dispersive X-ray spectroscopy with CO and NO oxidation light-off measurements we investigated deactivation phenomena of Pt/Al2O3, Pd/Al2O3, and Pt-Pd/Al2O3 model diesel oxidation catalysts during stepwise hydrothermal aging. Aging induces significant particle sintering that results in a decline of the catalytic activity for all catalyst formulations. While the initial aging step caused the most pronounced deactivation and sintering due to Ostwald ripening, the deactivation rates decline during further aging and the catalyst stabilizes at a low level of activity. Most importantly, we observed pronounced morphological changes for the bimetallic catalyst sample: hydrothermal aging at 750 °C causes a stepwise transformation of the Pt-Pd alloy via core-shell structures into inhomogeneous agglomerates of palladium and platinum. Our study shines a light on the aging behavior of noble metal catalysts under industrially relevant conditions and particularly underscores the highly complex transformation of bimetallic Pt-Pd diesel oxidation catalysts during hydrothermal treatment.

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Section: Discussionmentioning

confidence: 99%

Effects of Hydrothermal Aging on CO and NO Oxidation Activity over Monometallic and Bimetallic Pt-Pd Catalysts

et al. 2021

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“…The surface energy f S is taken to be that of (100) Pd, 0.866 J m −2 (ref. 61 ) and is scaled by the surface dilation . Here, is the total surface strain given by and the surface projection operator is defined using the facet normal n i as P ij = δ ij − n i n j .…”

Section: Methodsmentioning

confidence: 99%

Avalanching strain dynamics during the hydriding phase transformation in individual palladium nanoparticles

et al. 2015

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Phase transitions in reactive environments are crucially important in energy and information storage, catalysis and sensors. Nanostructuring active particles can yield faster charging/discharging kinetics, increased lifespan and record catalytic activities. However, establishing the causal link between structure and function is challenging for nanoparticles, as ensemble measurements convolve intrinsic single-particle properties with sample diversity. Here we study the hydriding phase transformation in individual palladium nanocubes in situ using coherent X-ray diffractive imaging. The phase transformation dynamics, which involve the nucleation and propagation of a hydrogen-rich region, are dependent on absolute time (aging) and involve intermittent dynamics (avalanching). A hydrogen-rich surface layer dominates the crystal strain in the hydrogen-poor phase, while strain inversion occurs at the cube corners in the hydrogen-rich phase. A three-dimensional phase-field model is used to interpret the experimental results. Our experimental and theoretical approach provides a general framework for designing and optimizing phase transformations for single nanocrystals in reactive environments.

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“…In Table S2 † we report the values of the parameters used for tting the electrochemical response of the Pd/C and Cu@Pd/ C nanoparticles during the electro-oxidation of ethanol at different concentrations. Furthermore, we considered the surface energy of the palladium of 0.684 J m À2 for the crystallographic plane (111) 21 because, in previous works, we determined that was the predominant plane even though the composition of materials was Pd/C and Cu@Pd/C. 17,[21][22][23] We used the Laviron eqn (1) and the modied Laviron eqn (12) to calculate the amount of adsorbed molecules for each catalyst.…”

Section: Validation Of the Modied Laviron Equationmentioning

confidence: 99%

“…Furthermore, we considered the surface energy of the palladium of 0.684 J m À2 for the crystallographic plane (111) 21 because, in previous works, we determined that was the predominant plane even though the composition of materials was Pd/C and Cu@Pd/C. 17,[21][22][23] We used the Laviron eqn (1) and the modied Laviron eqn (12) to calculate the amount of adsorbed molecules for each catalyst. For the Pd/C catalyst, the results of the amount of molecules adsorbed using the implicit method between Laviron and modied Laviron equations show an increase when the concentration of ethanol increases (Fig.…”

Section: Validation Of the Modied Laviron Equationmentioning

confidence: 99%

Size and surface-energy dependence of the adsorption/desorption equilibrium in ethanol electro-oxidation by Pd-nanoparticles. Theory and experiment

et al. 2022

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Surface properties of platinum and palladium

Cited by 18 publications

References 2 publications

Effects of Hydrothermal Aging on CO and NO Oxidation Activity over Monometallic and Bimetallic Pt-Pd Catalysts

Effects of Hydrothermal Aging on CO and NO Oxidation Activity over Monometallic and Bimetallic Pt-Pd Catalysts

Avalanching strain dynamics during the hydriding phase transformation in individual palladium nanoparticles

Size and surface-energy dependence of the adsorption/desorption equilibrium in ethanol electro-oxidation by Pd-nanoparticles. Theory and experiment

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