Research

Surface Chemistry and Catalysis

Our research focuses on the fundamental understanding of working mechanisms of nano-materials used in catalytic processes related to energy production and atmospheric pollutant control using modern surface science techniques under ultrahigh vacuum conditions. The catalytic systems include oxides and oxide-supported metal nanoparticles. Of particularly interest is to understand the relationship between catalyst surface structure and reactivity to provide knowledge for improving the performance of existing catalysts as well as for designing of new catalytic materials and technology. Surface science techniques used in the research include X-ray photoemission spectroscopy (XPS), temperature programmed desorption (TPD), low energy electron diffraction (LEED) and scanning tunneling microscopy (STM).

Current Research Topics

I. Structure-dependent chemistry of oxides

II. Surface chemistry of oxide-supported metal catalysts

III. Imaging molecular adsorbates, intermediates, products and surface active sites

Surface Science Techniques and Functions

Scanning tunneling microscopy can provide structural and electronic properties of catalytic systems at the micrometer/atomic scale. It also can be utilized to monitor detailed surface processes in situ during a catalytic reaction.

X-ray photoelectron spectroscopy is a useful technique for determining surface elemental compositions and their oxidation states. It can identify adsorbed surface species and their molecular environments during a catalytic reaction.

Low energy electron diffraction can be used to characterize the long-range order of catalytic surfaces as well as adsorbed reactant molecules.

Temperature-programmed desorption can be used to monitor reaction products and provide information regarding reaction kinetics and mechanism.