in the present study, tin-promoted pd/mwnts nanocatalystwas synthesized via polyol technique for application in hydrogenation of high-concentrated acetylene feedstocks. tem images showed a restricted distribution of nanoparticles in the range of 3-5 nm. the results indicated that nanoparticles sizes were resistant to further catalyst deactivation. xrd patterns signified alloying between pd and ...

In the present study, tin-promoted Pd/MWNTs nanocatalystwas synthesized via polyol technique for application in hydrogenation of high-concentrated acetylene feedstocks. TEM images showed a restricted distribution of nanoparticles in the range of 3-5 nm. The results indicated that nanoparticles sizes were resistant to further catalyst deactivation. XRD patterns signified alloying between Pd and ...

Iridium complexes were synthesized on MgO powder by adsorption of Ir(C(2)H(4))(2)(acac) [acac = acetonylacetonate]; images determined by aberration-corrected scanning transmission electron microscopy show individual Ir atoms, demonstrating that the supported complexes were site-isolated.

Four crystalline, porous metal-organic frameworks (MOFs), based on a new hexatopic linker, 1',2',3',4',5',6'-hexakis(4-carboxyphenyl)benzene (H6CPB), were synthesized and fully characterized. Interestingly, two members of this series exhibited new topologies, namely, htp and hhp, which were previously unseen in MOF chemistry. Gas adsorption measurements revealed that all members exhibited high ...

The chemisorptive behavior of CO on Pd-Au alloy films has been studied by infrared reflection-adsorption spectroscopy (IRAS). Geometric (ensemble) and electronic (ligand) effects have been addressed by comparing the results with the corresponding single-component systems. A unique CO vibrational feature at 2088 cm-1 is associated with CO adsorption on isolated Pd sites. Considering the frequenc...

plane-wave pseudopotential density functional theory (oft) periodic slab calculations were performed usingthe giteralized gradient approximation (gha) to investigate the adsorption of nitric oxide(no) on the (i ii)surface of cu. copper rface was stimulated using th p 'odic slab method consisting of five atomic layers.four different adsorption saes (atop. bridge, rcp hollow, and fcc hollow) were...

The interaction of water with Fe3O4(001) is studied by density functional theory calculations including an on-site Coulomb term. For isolated molecules, dissociative adsorption is strongly promoted at surface defect sites, while at higher coverages a hydrogen-bonded network forms with alternating molecular and dissociated species. This mixed adsorption mode and a suppression of the (square root...

We report on the magnetic coupling between isolated Co atoms as well as small Co islands and Ni(111) mediated by an epitaxial graphene layer. X-ray magnetic circular dichroism and scanning tunneling microscopy combined with density functional theory calculations reveal that Co atoms occupy two distinct adsorption sites, with different magnetic coupling to the underlying Ni(111) surface. We furt...

Numerical simulations examining chemical interactions of water molecules with forsterite grains have demonstrated the efficacy of nebular gas adsorption as a viable mechanism for water delivery to the terrestrial planets. Nevertheless, a comprehensive picture detailing the water-adsorption mechanisms on forsterite is not yet available. Towards this end, using accurate first-principles density f...

The contribution of variable grain sizes to uranium adsorption/desorption was studied using a sediment from the US DOE Hanford site. The sediment was wet sieved into four size fractions: coarse sand (1-2 mm), medium sand (0.2-1 mm), fine sand (0.053-0.2 mm), and clay/silt fraction (<0.053 mm). For each size fraction and their composite (sediment), batch and flow-cell experiments were performed ...