The Interaction of Water with Solid Surfaces: Fundamental Aspects Revisited

Ultrathin metal films and particles on oxide surfaces: structural, electronic and chemisorptive properties

While inert as bulk material, nanoscale gold particles dispersed on oxide supports exhibit a remarkable catalytic activity. Temperature-programmed reaction studies of the catalyzed combustion of CO on size-selected small monodispersed Aun (n ≤ 20) gold clusters supported on magnesia, and first-principle simulations, reveal the microscopic origins of the observed unusual catalytic activity, with Au8 found to be the smallest catalytically active size. Partial electron transfer from the surface to the gold cluster and oxygen-vacancy F-center defects are shown to play an essential role in the activation of nanosize gold clusters as catalysts for the combustion reaction.

https://www.physics.gatech.edu/files/u26/papers/0228.pdf

When Gold Is Not Noble: Nanoscale Gold Catalysts

Surface studies of supported model catalysts

A study of particle size effects during the catalytic CO2 electroreduction on size-controlled Cu nanoparticles (NPs) is presented. Cu NP catalysts in the 2–15 nm mean size range were prepared, and their catalytic activity and selectivity during CO2 electroreduction were analyzed and compared to a bulk Cu electrode. A dramatic increase in the catalytic activity and selectivity for H2 and CO was observed with decreasing Cu particle size, in particular, for NPs below 5 nm. Hydrocarbon (methane and ethylene) selectivity was increasingly suppressed for nanoscale Cu surfaces. The size dependence of the surface atomic coordination of model spherical Cu particles was used to rationalize the experimental results. Changes in the population of low-coordinated surface sites and their stronger chemisorption were linked to surging H2 and CO selectivities, higher catalytic activity, and smaller hydrocarbon selectivity. The presented activity–selectivity–size relations provide novel insights in the CO2 electroreduction r...

J.-W. He

Papers

Synthesis and characterization of ultra-thin MgO films on Mo(100)

XPS characterization of ultra-thin MgO films on a Mo(100) surface

X-ray photoelectron spectroscopic characterization of ultra-thin silicon oxide films on a Mo(100) surface

Preparation and characterization of ultra-thin iron oxide films on a Mo(100) surface

Overlayer growth and chemisorptve properties of ultra-thin Fe films on W(110) and W(100)