Gary Haller

Gary Haller's picture
Professor Emeritus of Chemical and Environmental Engineering
203 432 4378

ChE & EnvE Engineering & Chemistry 
Member of Yale faculty since 1967


The goal of our research has been to understand and rationalize heterogeneous catalytic activity and selectivity in terms of surface or catalytic site structure. Surface and/or site structure primarily requires spectroscopic characterization, but this is usually accompanied by physi- and chemisorption and model catalytic activity studies. We are currently investigating a variety of catalysts based on structured carbon supports, specifically on single- and multi-walled carbon nanotubes (SWCNT and MWCNT).

Carbon supports, e.g., MWCNT, have a particularly desirable property of stability, relative to oxides, in hot liquid water, the medium for most biomass refining and processing. Grafted nanoparticles of oxides on MWCNT, e.g., ZrO2/MWCNT, can also be hydrothermally stable for ZrO2 particles of a few nm isolated on the hydrophobic MWCNT support. Acid sites can be created by sulfated or tungstated ZrO2 and co-supported metals, e.g., Ni, provide bi-functional sites for hydrolysis (acid function) and hydrogenation (metal function) required for biomass processing in liquid water at temperatures in the range of 200°C.

Integrated, multi-catalysts processes for methanol-to-gasoline (MTG) and methanol-to-olefins (MTO) are studied in connection with consulting and a visiting professorship at the Technical University of Munich.


B.S. University of Nebraska, Kearney, 1962
Ph.D. Northwestern University, 1966
NATO Postdoctoral Fellow, Oxford University, 1966-67


Donald E. Fox Chemistry Lectureship, University of Nebraska, Kearney, 1982
Outstanding Alumni Award, University of Nebraska, Kearney, 1988
The George C.A. Schuit Lectureship, Center for Catalytic Science and Technology, University of Delaware, 1990
Catalysis Society of Metropolitan New York Award for Excellence in Catalysis, sponsored by Exxon Research and Engineering Company, 1993
Yale Science and Engineering Association Meritorious Service Award, 1995
Robert Burwell Lectureship, The Catalysis Society, sponsored by Amoco, 1995
Harry Fair Lectureship, University of Oklahoma, 1995
Ipatieff Lectureship, Northwestern University, 1996
Lacy Lectureer in Chemical Engineering, California Institute of Technology, 1996
NIOK (Neterlands Institeu for Catalysis Research), Lecturer (Guest Teacher), 1996
Professeur Invité à l’Université Pierre et Marie Curie (Paris VI), 1996

Recent Publications

C. Liu, T. Bolin, P. Northrup, S. Lee, C. McEnally, P. Kelleher, L. Pfefferle,& G.L.  Haller. Combined Zr and S XANES analysis on S-ZrO2/MWCNT solid acid catalyst. Topics in Catalysis 2014, 57, 693-705.

C. Liu, L.D. Pfefferle, & G.L. Haller. The electronic structure or charge delocalization of sulfated zirconia (supported on multi-walled carbon nanotubes): Acid sites probed by X-ray absorption spectroscopy. Topics in Catalysis 2014, 57, 774-784.

X. Sun, S. Mueller, Y. Liu, H. Shi, G.L. Haller, M. Sanchez-Sanchez, A.C. van Veen, & J.A. Lercher. On reaction pathways in the conversion of methanol to hydrocarbons on HZSM-5. J. Catal. 2014, 317, 185-197.

Z. Zhang, L. Pfefferle, & G.L. Haller. Characterization of functional groups on oxidized multi-wall carbon nanotubes by potentiometric titration. Catal. Today 2015, 249, 23-29.

S. Mueller, Y. Liu, M. Vishnuvarthan, X. Sun, A.C. van Veen, G.L. Haller, M. Sanchez-Sanchez, & J.A. Lercher. Coke formation and deactivation pathways on H-ZSM-5 in the conversion of methanol to olefins J. Catal. 2015, 325, 48-59.

Research Interests