Carnegie Mellon University

Neil Donahue

Neil M. Donahue

Thomas Lord University Professor in Chemistry
Professor, Chemical Engineering
Professor, Engineering and Public Policy
Director, Steinbrenner Institute for Environmental Education and Research


Ph.D. Meteorology, MIT, 1991


Atmospheric chemistry, organic aerosol, kinetics, reaction dynamics, radical-molecule reactivity, ozonolysis, mass spectrometry


Atmospheric Chemistry: Ozonolysis and Organic Aerosols.

His principal interest is in the oxidation chemistry of Earth's atmosphere — specifically the oxidation of organic compounds and the associate radical processes in the atmosphere. Two closely connected areas are ozonolysis chemistry and the chemistry controlling organic-aerosol levels and properties in the atmosphere. Aerosols — fine particulate matter, or PM — are of interest for two major reasons: particles play a central role in climate, and they kill people. The leading uncertainty on the forcing side of climate science is the degree to which cloud properties have changed between 1850 and now due to changes in the number concentrations of fine, water-soluble particles that act as cloud-condensation nuclei (CCN). Also, approximately 50,000 people die prematurely each year in the U.S. alone from inhalation of elevated levels of fine PM. More than half of the fine PM mass is composed of a very complex mixture of highly oxidized organic compounds. They are water soluble and have unknown health effects but appear to correlate positively with observed health endpoints.

Recent research largely directed by Prof. Donahue within the Center for Atmospheric Particle Studies (CAPS) has established that organic aerosol exists in a dynamic balance connecting phase partitioning and oxidation chemistry. Oxidation of large, reduced organics typical of fresh emissions tends to functionalize the carbon backbone, leading to lower vapor pressure products that spend more time in the particulate (condensed) phase, but continued oxidation tends to fragment the carbon backbone as it drives the products towards the oxidative endpoint — CO2. Understanding this multiphase chemistry in the extremely rich and complex mixture that is organic aerosol is a major current research focus.

In parallel, the Donahue group is pursuing the short-lived intermediates involved in gas-phase ozonolysis chemistry, including the carbonyl-oxide (Criegee Intermediate). Reactions in the gas phase show a strong dependence on both pressure and the carbon number because energy transfer from highly-excited reaction products via collisions with the bath gas is inefficient. The group uses both experimental (spectroscopic) and theoretical (quantum chemistry coupled to statistical reaction dynamics) tools to probe the nature and fate of these intermediates.


Role of iodine oxoacids in atmospheric aerosol nucleation
X.-C. He … N. M. Donahue et al. Science 371, 589–595 2021

Peroxy radical kinetics and new particle formation
M. Schervish and N. M. Donahue. Environmental Science: Atmospheres 1, 79 – 92 2021

Measurement of iodine species and sulfuric acid using bromide chemical ionization mass spectrometers
M. Wang, X.-C. He, H. Finkenzeller, S. Iyer, D. Chen, J. Shen, M. Simon, V. Hofbauer, J. Kirkby, J. Curtius, N. Maier, T. Kurten, D. R. Worsnop, M. Kulmala, M. Rissanen, R. Volkamer, Y. J. Tham, N. M. Donahue, and M. Sipila. Atmospheric Measurement Techniques 14, 4187–4202 2021

Impact of urban pollution on organic-mediated new-particle formation and particle number concentration in the Amazon rainforest
B. Zhao, J. D. Fast, N. M. Donahue, M. Shrivastava, M. Schervish, J. E. Shilling, H. Gordon, J. Wang, Y. Gao, R. A. Zaveri, Y. Liu, and B. Gaudet. Environmental Science & Technology 55, 4357–4367 2021

Rapid growth of new atmospheric particles by nitric acid and ammonia condensation
M Wang, W Kong, R Marten, XC He, D Chen, J Pfeifer, N Donahue, et al. Nature, 2020

Primary ion diffusion charging and particle wall loss in smog chamber experiments
Naser G. A. Mahfouz & Neil M. Donahue. Aerosol Science and Technology, 2020 54:9, 1058-1069

Peroxy radical chemistry and the volatility basis set
Meredith Schervish and Neil M. Donahue. Atmospheric Chemistry and Physics, 20, 1183–1199, 2020

High concentration of ultrafine particles in the Amazon free troposphere produced by organic new particle formation
Bin Zhao, Manish Shrivastava, Neil M. Donahue, Hamish Gordon, Meredith Schervish, John E. Shilling, Rahul A. Zaveri, Jian Wang, Meinrat O. Andreae, Chun Zhao, Brian Gaudet, Ying Liu, Jiwen Fan, Jerome D. Fast. Proceedings of the National Academy of Sciences 2020, 117 25344-25351

Moving beyond Fine Particle Mass: High-Spatial Resolution Exposure to Source-Resolved Atmospheric Particle Number and Chemical Mixing State
Qing Ye, Hugh Z. Li, Peishi Gu, Ellis S. Robinson, Joshua S. Apte, Ryan C. Sullivan, Allen L. Robinson, Neil M. Donahue, and Albert A. Presto, Environmental Health Perspectives 128 January 2020

Molecular identification of organic vapors driving atmospheric nanoparticle growth
Claudia Mohr, Joel A Thornton, Arto Heitto, Felipe D Lopez-Hilfiker, Anna Lutz, Ilona Riipinen, Juan Hong, Neil M Donahue, Mattias Hallquist, Tuukka Petäjä, Markku Kulmala, Taina Yli-Juuti, Nauret Communications 10, 4442 2019

Using Ionic Liquids to Study the Migration of Semivolatile Organic Vapors in Smog Chamber Experiments
Qing Ye, Ryan C Sullivan, Neil M Donahue, J. Phys. Chem.2019, 123, 17, 3887-3892

Highly oxygenated organic molecules (HOM) from gas-phase autoxidation involving peroxy radicals: A key contributor to atmospheric aerosol
Federico Bianchi, Theo Kurtén, Matthieu Riva, Claudia Mohr, Matti P Rissanen, Pontus Roldin, Torsten Berndt, John D Crounse, Paul O Wennberg, Thomas F Mentel, Jürgen Wildt, Heikki Junninen, Tuija Jokinen, Markku Kulmala, Douglas R Worsnop, Joel A Thornton, Neil Donahue, Henrik G Kjaergaard, Mikael Ehn, Chem. Rev. 2019, 119, 6, 3472-3509 2019

Rapid growth of organic aerosol nanoparticles over a wide tropospheric temperature range
Stolzenburg, Dominik, Lukas Fischer, Alexander L. Vogel, Martin Heinritzi, Meredith Schervish, Mario Simon, Andrea C. Wagner, Neil M. Donahue et al., Proceedings of the National Academy of Sciences 2018, 115, 9122-9127

Spatial Variability of Sources and Mixing State of Atmospheric Particles in a Metropolitan Area
Ye, Qing, Peishi Gu, Hugh Z. Li, Ellis S. Robinson, Eric M. Lipsky, Christos Kaltsonoudis, Alex KY Lee, Neil M. Donahue et al., Environmental Science & Technology 2018

Measurement–model comparison of stabilized Criegee intermediate and highly oxygenated molecule production in the CLOUD chamber
Sarnela, Nina, Tuija Jokinen, Jonathan Duplissy, Chao Yan, Tuomo Nieminen, Mikael Ehn, Siegfried Schobesberger, Neil M. Donahue et al., Atmospheric Chemistry and Physics 2018, 18, 2363-2380

Secondary organic aerosol production from pinanediol, a semi-volatile surrogate for first-generation oxidation products of monoterpenes
Ye, Penglin, Yunliang Zhao, Wayne K. Chuang, Allen L. Robinson, and Neil M. Donahue, Atmospheric Chemistry and Physics 2018, 18(9), 6171-6186

Influence of temperature on the molecular composition of ions and charged clusters during pure biogenic nucleation
Frege, Carla, Ismael K. Ortega, Matti P. Rissanen, Arnaud P. Praplan, Gerhard Steiner, Martin Heinritzi, Lauri Ahonen et al., Atmospheric Chemistry and Physics 2018, 18(1), 65-79

Unimolecular Decay of the Dimethyl-Substituted Criegee Intermediate in Alkene Ozonolysis: Decay Time Scales and the Importance of Tunneling
Greg T. Drozd, Theo Kurtén, Neil M. Donahue, and Marsha I. Lester, The Journal of Physical Chemistry A 2017 121 (32), 6036-6045

Mass accommodation coefficients of fresh and aged biomass-burning emissions
Aditya Sinha, Rawad Saleh, Ellis S. Robinson, Adam T. Ahern, Daniel S. Tkacik, Albert A. Presto, Ryan C. Sullivan, Allen L. Robinson & Neil M. Donahue, Aerosol Science and Technology Vol. 0, Iss. 0, 2018

Reducing secondary organic aerosol formation from gasoline vehicle exhaust
Yunliang Zhao, Rawad Saleh, Georges Saliba, Albert A. Presto, Timothy D. Gordon, Greg T. Drozd, Allen H. Goldstein, Neil M. Donahue and Allen L. Robinson, Proceedings of the National Academy of Sciences 2017 July, 114 (27) 6984-6989


Years Position
2015–present Thomas Lord Professor in Chemistry, Professor of Chemical Engineering, and Engineering and Public Policy
2013–present Director, Steinbrenner Institute for Environmental Education and Research
2008–2015 Professor of Chemistry, Chemical Engineering, and Engineering and Public Policy, Carnegie Mellon University
2005–2008 Associate Professor of Chemistry and Chemical Engineering, Carnegie Mellon University
2005–2013 Director, Center for Atmospheric Particle Studies
2000–2005 Assistant Professor of Chemistry and Chemical Engineering, Carnegie Mellon University
1991–2000 Postdoctoral Associate and Research Scientist, Harvard University

Awards and Distinctions

Years Award
2017 Carnegie Science Award, Environmental Award
2017 2017 Esselen Award, Northeastern Section of the American Chemical Society
2016 ACS Pittsburgh Award
2011 Fellow, American Geophysical Union
2010 Carnegie Institute of Technology Outstanding Research Award
1991–1993 DOE Distinguished Postdoctoral Fellow
1985–1988 NASA Graduate Student Researcher
1985 MIT Jule Charney Award