Investigators and Program Directors
Lei Zhu
Research Scientist, Wadsworth Center, Inorganic and Nuclear Chemistry
Associate Professor, School of Public Health, Environmental Health Sciences
Ph.D., Physical Chemistry, Columbia University (1991)
Enrico Fermi Scholar, Chemistry Division, Argonne National
Laboratory (1991-1993)
E-mail: zhul@wadsworth.org
Research Interests
Organic compounds and nitrogen oxides (NOx) are emitted into the atmosphere by natural and anthropogenic sources. They play central roles in a variety of environmental processes such as ground-level ozone formation, stratospheric ozone depletion, acid deposition, and global climate change. My primary research objective is to determine quantitatively the kinetics, mechanisms, and products of homogeneous and heterogeneous atmospheric reactions related to organic compounds and reactive nitrogen species, NOY, where NOY is defined as the sum of NOx and the atmospheric oxidation products of NOx. Understanding atmospheric chemistry of organic compounds and reactive nitrogen species is vital to pollution prevention and control efforts.
In the past few years, we carried out an NSF funded research project on the kinetics and photochemistry of homogeneous and heterogeneous atmospheric aldehyde reactions. Aldehydes play a key role in the formation of photochemical smog and ground-level ozone. Their photodissociation is an important source of odd hydrogen radicals (HOx=OH+HO2) in the atmosphere. Photolysis quantum yields of aldehydes exhibit dramatic wavelength dependence in the actinic UV region. My group has studied wavelength-dependent photolysis of unsubstituted aliphatic aldehydes (propionaldehyde, n-butyraldehyde, i-butyraldehyde, n-pentanal, i-pentanal, t-pentanal, n-hexanal, and n-heptanal), aromatic aldehyde (benzaldehyde), and saturated and unsaturated dicarbonyls (glyoxal, methylglyoxal, butenedial, and 4-oxo-2-pentenal) in the actinic UV region by combining laser photolysis with a sensitive, time-resolved absorption technique, cavity ring-down spectroscopy. My group in collaboration with Dr. Liang T. Chu at the Wadsworth Center has also applied cavity ring-down technique to study acetaldehyde photolysis on ice films at 243 K. Our work has indicated that the photolysis of aldehydes on snow and ice surfaces will likely contribute to HOX formation in the atmosphere. Our work has also demonstrated the feasibility of using cavity ring-down technique to study surface photochemical processes.
Contact Information
Phone: (518) 474-6846
Fax: (518) 473-2895
E-mail: zhul@wadsworth.org.