Hydrogen on Pd(100)-S: the effect of sulfur on precursor mediated adsorption and desorption

Ab Initio Molecular Dynamics Simulations of the Adsorption of H2 on Palladium Surfaces

“…On Pd(100), sulfur adsorption leads to a significant reduction of the hydrogen dissociation probability. [8,9] Because of the presence of sulfur, H 2 dissociation on Pd is no longer non-activated. [8,9,40] Figure 5 shows a two-dimensional cut through the PES of H 2 interacting with S(22)/Pd(100) derived from PAW-DFT calculations.…”

“…However, not only the coverage of the considered adsorbents itself can influence the adsorption probability, but also the coadsorption of other species can poison or promote reactions on surfaces. On Pd, in particular the influence of sulfur on the hydrogen-Pd interaction dynamics was studied both experimentally [8,9,39,40] as well as theoretically, [40][41][42][43][44][45] but CO coadsorption was also considered. [46] The H 2 -Pd dynamics on low-index metal surfaces has usually been treated quantum mechanically because of the light mass of hydrogen, [2,11,12,16,[47][48][49] but classical dynamical studies have also been performed.…”

The effect of H2S on the performance of Pd and Pd/Au composite membrane

“…It should be noted that the site blocking effect by adsorbed sulfur refers not only to the simple geometric blocking of adsorption sites but also the electronic blocking effect, due to the adsorbed sulfur generating an energy barrier for H 2 dissociative adsorption and diffusion. As a result, each adsorbed sulfur effectively blocks 4-13 sites for H 2 adsorption [11][12][13]. Based on the percentage of the observed permeance loss, the sulfur coverage on membrane M3 was approximately between 0.06 and 0.21 ML (monolayer).…”

“…The adsorbed sulfur blocked the adsorption sites on the Pd surface and generated an energy barrier where each adsorbed sulfur effectively blocked 4-13 sites for the H 2 adsorption [11][12][13]. In addition, the adsorbed sulfur could incorporate with Pd to form bulk Pd 4 S depending on the H 2 S exposure conditions.…”

Pd-Alloy membranes for hydrogen separation

“…While H 2 S dissociates on the surface to form HS and S species, the fit of the microkinetic model did not improve when decomposition steps were added, suggesting rapid reversibility (at least in the presence of significant H 2 partial pressures). Adsorbed S is known to deactivate nearby sites [37,38] …”