The interaction of hydrogen with many transition metal surfaces is characterized by a coexistence of activated with non-activated paths to adsorption with a broad distribution of barrier heights. By performing six-dimensional quantum dynamical calculations using a potential energy surface derived from ab initio calculations for the system H2/Pd(100) we show that these features of the potential ...

Adsorption and co-adsorption of ethylene, acetylene and hydrogen on Pd-Ag particles, supported on thin alumina films, have been studied by temperature programmed desorption (TPD). The TPD results show that adding of Ag to Pd suppresses overall hydrogenat ion activity but increases selectivity towards ethylene, i.e. similar to that observed on real catalysts. The results are rationalized on the ...

We combine experimental observations with ab initio calculations to study the reversible hydrogenation of single-wall carbon nanotubes using high boiling polyamines as hydrogenation reagents. Our calculations characterize the nature of the adsorption bond and identify preferential adsorption geometries at different coverages. We find the barrier for sigmatropic rearrangement of chemisorbed hydr...

We have clarified the adsorption and release mechanism of hydrogen to/from Pt clusters on an MCM-41 surface by using the XAFS technique. After reduction, the icosahedral Pt13 cluster of r(Pt-Pt) =0.273 nm is formed. In contrast, a very small oxidized metal particle of r(Pt-Pt) = 0.254 nm is formed after the oxidation. We have measured time-resolved energy dispersive XAFS in order to clarify the...

We present a first-principles study of geometrical structure and energetics of hydrogen adsorbed on hexagonal single-walled silicon nanotubes (SiNTs). The adsorption behaviors of hydrogen molecules in SiNTs are investigated. The binding energies for the most stable physisorbed configurations are calculated to be less than 0.1 eV. The energy barriers are also investigated for dissociation of H2 ...

In order for hydrogen gas to be used as a fuel, it must be stored in sufficient quantity on board the vehicle. Efforts are being made to increase the hydrogen storage capabilities of metal-organic frameworks (MOFs) by introducing unsaturated metal sites into their linking element(s), as hydrogen adsorption centers. In order to devise successful hydrogen storage strategies there is a need for a ...

The structural changes in Pd and Pd–Ru alloys induced by the repeated absorption–desorption of hydrogen have been studied. It is found that absorption–desorption cycles produce structural changes in Pd whereas the addition of small amounts of Ru inhibits these hydrogen-induced changes. The experimental results show that bulk hydrogen absorption occurs in Pd, while hydrogen surface adsorption be...

Based on recently published papers, this article introduces the characteristics, hydrogen storage capacity, and economic advantages of the adsorptive carbon system, zeolite, and glass microspheres as possible methods of hydrogen storage. The adsorbents for hydrogen storage now available on the market are activated carbon and zeolite. In terms of hydrogen adsorption, zeolite can adsorb 1 wt perc...