Gary L. Haller
Website:Haller and Pfefferle Lab Group
Ph.D., Northwestern University
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.
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(6-9), 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(6-9), 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.
- "Growth of Nanostructures with Controlled Diameter," US patent 7,485,279 B2, Feb. 3, 2009.
- "Controlled Growth of Single-wall Carbon Nanotubes," US patent 7,357,983 B2, Apr. 15, 2008.
- Visiting Fellow, Institute for Advanced Study, Technical University of Munich
- Director, Henry Koerner Center for Emeritus Faculty, Yale University