Energy Research

Our research has helped to understand the redox reactions of important small molecules like N2, CO2, and hydrocarbons. We often use strategies that are inspired by natural enzymes, in particular the ways that inexpensive metals can be used.

In a key example of this strategy, we developed nickel catalysts for the reduction of protons to hydrogen (H2). Hydrogen has great promise as a “clean fuel” that burns to give only water, and is a raw material for many industrial processes (including the Haber-Bosch process for nitrogen reduction). However, most H2 used today comes from fossil fuel, and it is important to develop renewable sources. Since nickel catalysts are inexpensive, they are particularly promising.

So far, we have achieved proton reduction using solar energy, through collaborations with Richard Eisenberg and Todd Krauss at the University of Rochester. These experiments use a light-harvesting molecule (“chromophore”), an electron donor, and a catalyst. Under light, H2 is produced. Using photophysical and electrochemical methods, we made several advances in understanding the stability and reactivity of catalysts with cobalt and nickel. Using CdSe quantum dots, we developed the first homogeneous systems that can form H2 for weeks without decomposition.

In continued research on this topic, we seek renewable catalysts for other value-added processes leading to solar fuel formation.

Relevant Publications

Amit Das, Zhiji Han, William W. Brennessel, Patrick L. Holland, Richard Eisenberg
Nickel Complexes for Robust Light-Driven and Electrocatalytic Hydrogen Production from Water
ACS Catal.  20155, 1397-1406.  
Zhiji Han, Luxi Shen, William W. Brennessel, Patrick L. Holland, Richard Eisenberg
Nickel Pyridylthiolate Complexes for the Photocatalytic Production of Hydrogen from Aqueous Solutions in Noble-Metal-Free Systems
J. Am. Chem. Soc.  2013135, 14659-14669.  
Zuofeng Chen, Christopher R. K. Glasson, Patrick L. Holland, Thomas J. Meyer
Electrogenerated polypyridyl ruthenium hydride and ligand activation for water reduction to hydrogen and acetone to iso-propanol
Phys. Chem. Chem. Phys.  201315, 9503-9507.  
Zhiji Han, Fen Qiu, Richard Eisenberg, Patrick L. Holland, Todd D. Krauss
Robust Photogeneration of H2 in Water Using Semiconductor Nanocrystals and a Nickel Catalyst
Science  2012338, 1321 1324.  
Christopher R. K. Glasson, Wenjing Song, Dennis L. Ashford, Aaron Vannucci, Zuofeng Chen, Javier J. Concepcion, Patrick L. Holland, Thomas J. Meyer
Self-Assembled Bilayers on Indium-Tin Oxide (SAB-ITO) Electrodes: A Design for Chromophore-Catalyst Photoanodes
Inorg. Chem.  201251, 8637-8639.  
William R. McNamara, Zhiji Han, Chih-Juo Yin, William W. Brennessel, Patrick L. Holland, Richard Eisenberg
Cobalt-Dithiolene Complexes for the Photocatalytic and Electrocatalytic Reduction of Protons in Aqueous Solutions
Proc. Natl. Acad. Sci. USA   2012109, 15594-15599.  
Zhiji Han, William R. McNamara, Min-Sik Eum, Patrick L. Holland, Richard Eisenberg
A Nickel Thiolate Catalyst for the Long-Lived Photocatalytic Production of Hydrogen in a Noble-Metal-Free System
Angew. Chem. Int. Ed.   201251, 1667-1670.  
Theresa M. McCormick, Zhiji Han, David J. Weinberg, Patrick L. Holland, Richard Eisenberg
The Impact of Ligand Exchange in Hydrogen Production from Cobaloxime-Containing Photocatalytic Systems
Inorg. Chem.  201150, 10660-10666.  
William R. McNamara, Zhiji Han, Paul J. Alperin, William W. Brennessel, Patrick L. Holland, Richard Eisenberg
Cobalt-Dithiolene Complex for the Photocatalytic and Electrocatalytic Reduction of Protons
J. Am. Chem. Soc.  2011133, 5123-5132.  
Matthew P. McLaughlin, Theresa M. McCormick, Richard Eisenberg, Patrick L. Holland
A stable molecular nickel catalyst for the homogeneous photogeneration of hydrogen in aqueous solution
Chem. Commun.   201147, 7989-7981.  
Azwana R. Sadique, William W. Brennessel, Patrick L. Holland
A diketiminate-bound diiron complex with a bridging carbonate ligand
Acta Cryst. C  200965, m174-m176.  
Azwana R. Sadique, William W. Brennessel, and Patrick L. Holland
Reduction of COto CO Using Low-Coordinate Iron: Formation of a Four-Coordinate Iron Dicarbonyl Complex and a Bridging Carbonate Complex
Inorg. Chem.   200847, 784-786.