Cooperative electrocatalytic alcohol oxidation with electron-proton transfer mediators
Developing new strategies to power fuel cells with biomass rather than hydrogen gas.
The electrochemical oxidation of alcohols is a major focus of energy and chemical conversion efforts, with potential applications ranging from fuel cells to biomass utilization and chemical synthesis.
This research studied the electrochemical oxidation of alcohols, and found a pair of catalysts that oxidize alcohols with significantly better energy efficiency. In the long term, this research could be the basis for using biomass rather than hydrogen gas in fuel cells.
Researchers in the Great Lakes Bioenergy Research Center examined the electrochemical oxidation of alcohols and identified a cooperative catalyst system, with two components capable of moving two electrons using the same energy needed to move one electron. One of the components is the organic nitroxyl TEMPO, while the other one is a molecuar copper complex (Cu(bpy)). The co-catalyst system represents a unique class of electrocatalysts for alcohol oxidation, and in the case of the Cu(bpy)-TEMPO, the modular composition of that electrocatalyst makes it well suited for further optimization and development. The (bpy)Cu/nitroxyl catalysts studied exhibited substantially higher rates than the widely used TEMPO-only catalyst for all substrates tested, including excellent reactivity with methanol and ethanol. By working with a first-row transition metal (such as bpy(Cu)), electron-proton transfer mediators provide the basis for efficient proton-coupled 2-electron reactivity, and it can lead to much faster electrocatalytic rates and lower overpotentials, both of which are crucial in energy-conversion applications.
Contacts (BER PM)
N. Kent Peters
Program Manager, Office of Biological and Environmental Research
University of Wisconsin-Madison
The DOE Great Lakes Bioenergy Research Center is supported by the US Department of Energy, Office of Science, Office of Biological and Environmental Research, through contract number DE-FC02-07ER64494.