Our research interest is mainly focused on the development of infrared photodissociation and photoelectron spectroscopy based on table-top OPO/OPA Laser, Infrared Free Electron Laser, Vacuum Ultraviolet Free Electron Laser, and their applications to the studies on the structure and dynamics of the clusters with relevance of catalysis and atmospheric chemistry.
(1) Experimental methods:
Infrared photodissociation (IRPD) spectroscopy
Infrared-Vacuum Ultraviolet (IR-VUV) spectroscopy
Photoelectron spectroscopy (PES)
Infrared Free Electron Laser (IR-FEL)
Vacuum Ultraviolet Free Electron Laser (VUV-FEL)
(2) Theoretical methods:
Quantum chemical calculation
Molecular dynamics simulation
(1) Structure-reactivity Relationship of Clusters
A number of key reaction intermediates are often involved in the catalytic reaction processes. Due to the low number density and short lifetime of these species, the methods with high sensitivity and transient detection are thus required to explore the structural and dynamic properties of the reaction intermediates. We use high-resolution reflectron time of flight mass spectrometer to capture reaction intermediates, and the high-sensitive infrared photodissociation spectroscopy and photoelectron spectroscopy to characterize the geometric and electronic structures of these key species to understand the elementary and catalytic reaction mechanism.
(2) Atmospheric Chemistry
Environmental pollution in the earth atmosphere is becoming a serious issue in the developing world as it is causing severe health and traffic problems for human society. Understanding the mechanism of aerosol growth is the prerequisite to control the atmospheric pollution problems. Generally, molecular clusters are formed initially between pollutant molecules and water molecules, and the clusters then grow in the atmosphere environment to form larger aerosol particles. A key issue in the study of aerosol science is how aerosol particles are formed initially in the atmosphere and how they grow under different conditions. The newly-built Dalian Coherent Light Source (DCLS) facility delivers vacuum ultraviolet free electron laser (VUV-FEL) with a continuously tunable wavelength region between 50 and 150 nm and high pulse energy, and makes it possible to detect neutral complexes with a broad range of ionization potentials. In this lab, the near-threshold ionization mass spectrometry based on the unique VUV-FEL is utilized to study the structure of aerosol particles and unravel the mechanism of aerosol nucleation processes.