Size-dependent hydrogen trapping in palladium nanoparticles

Abstract

We report an experimental study, supported by a theoretical approach based on simulations, to explore the phenomenon of H trapping in small Pd nanoparticles. Hydrogen absorption/desorption of a series of...

Controlling the Reactivity and Interactions between Hydrogen and Palladium Nanoparticles via Management of the Particle Diameter

“…In the meantime, the number of H atoms dissolved in the α‐PdH phase measured at 0.05 V decreases with the increase in the NPs size, from 0.06 to 0.05 and 0.04 for Pd NPs “S” , “M” , and “L” respectively. This result is in good agreement with the literature, as the solubility of H in the α‐PdH phase is expected to increase with decreasing NPs size, while the H sorption capacity in the β‐PdH phase is expected to decrease [5,29,35] . The observed behaviour is typical of Pd NPs, whereas an opposite trend is expected for Pd thin films.…”

“…The authors also claim that a sublayer rich in H atoms contributes greatly to the global H/Pd ratio in thin films. Some studies describe Pd hydride in NPs as a core‐shell structure, in which the outer shell, i. e. the subsurface, would present interstitial sites less favourable for the H absorption than the ones of the inner core [35] . In such a case, the number of interstitial sites suitable for H absorption decreases with the Pd NPs diameter, which would explain the opposite trend observed.…”

Addressing the CO2 challenge through thermocatalytic hydrogenation to carbon monoxide, methanol and methane

“…This is the case for magnesium oxide in Pd/MgO-SiO 2 catalyst, where the MgO is taking care of the CO 2 while the palladium dissociates the H 2 , making the metal-support interface a plausible active site. 281,282 The bifunctional mechanism of this system was confirmed by other works. 277 The replacement of magnesium with nickel or iron does not change significantly the CO 2 conversion.…”

Hydrogen-Intercalation-Induced Lattice Expansion of Pd@Pt Core–Shell Nanoparticles for Highly Efficient Electrocatalytic Alcohol Oxidation

“…More importantly, the atomically resolved HAADF-STEM image (Figure i) and the moiré images (Figure j 1 and j 2 ) show that the core–shell interface still remains fully epitaxial and coherent. Hydrogen intercalation can convert Pd to PdH 0.43 and induce a volume expansion of the core, − but the Pt shell still maintains the same composition since it is too inert to form the platinum hydride . Therefore, the as-observed continuous lattice at the core–shell interface in c -PdH 0.43 @Pt NPs indicates that the Pt shell is subject to a lattice expansion so that it can match the enlarged lattice of the core very well.…”