KSEA events The solid/gas and solid/liquid interface in the catalyst probed with Ambient-pressure X-ray Photoelectron Spectroscopy (190807 KSEA Berkeley Chapter Seminar)
TITLE: The solid/gas and solid/liquid interface in the catalyst probed with Ambient-pressure X-ray Photoelectron Spectroscopy (AP-XPS)
SPEAKER: Kyung-Jae Lee, PostDoctoral Researcher, Advanced Light Source, Berkeley
ABSTRACT: All the reaction with heterogeneous catalysts, including electrochemical catalysts, happens at the surface of the catalyst, i.e., solid/gas and solid/liquid interface. Therefore, many efforts have been conducted to observe the interface in operating condition to understand the reaction on the catalyst. X-ray Photoelectron Spectroscopy (XPS) is one of useful analytic tool for investigating the surface chemical state which is surface sensitive but has a limitation that it can be measured only in ultra-high vacuum condition. Ambient-pressure XPS (AP-XPS) overcomes this ‘pressure gap’ problem by applying a differential pump between the main chamber and analyzer, and as a result, the reactions with more realistic pressure condition could be studied. In this seminar, I would like to introduce the study of CO2 conversion reaction on Ni(100) probed with the combination of APXPS and Mass spectrometer (MS). The CO2 activation mechanism was deduced by changing a sequence of dosing gases, CO2 and H2, and the evolvement of surface species was observed with the combination of MS as changing the temperature to understand the reaction mechanism more deeply. Moreover, some of the recent studies of probing the solid/liquid interface in the electrochemical system will be presented briefly.
BIO: Dr. Kyung-Jae Lee is a PostDoc working with Prof. Simon Mun in Department of Physics and Photon Science at GIST, Korea and affiliated with Advanced Light Source of LBNL. He received Ph.D. and B.S. in Department of Chemical and Biological Engineering at Seoul National University, Korea. He is now working on the investigation of solid/liquid and solid/gas interfaces with ambient-pressure XPS.