Christopher Hahn

Associate Staff Scientist

Phone: 
650-926-8521

Global dependence on fossil fuels as energy sources and the alarming increase of greenhouse gas emissions has necessitated the development of carbon-free and carbon-neutral renewable energy sources for the future. The sequestration of CO2 emissions and the subsequent electrochemical reduction of CO2 into fuel products, forms a carbon-neutral synthetic fuel cycle which could potentially be streamlined into existing fuel infrastructures. To date, only Cu has displayed any propensity as a catalyst to electrochemically reduce CO2 into longer chain hydrocarbons, carboxylates, and alcohols. However, Cu generally requires a large overpotential to reduce CO2 and has little product selectivity as a catalyst. Recent theoretical work by SUNCAT indicates that scaling relations associated with reaction adsorbate binding energies could be limiting the CO2 reduction activity of transition metal catalysts. These studies suggest that alloying can improve the activity and selectivity of a CO2 reduction catalyst by decoupling the binding energies of specific reaction intermediates. In collaboration with theorists at SUNCAT, I use physical vapor deposition to synthesize a theory targeted library of alloy catalysts to screen for CO2 electroreduction activity, selectivity, and stability.

Publications

Development of a reactor with carbon catalysts for modular-scale, low-cost electrochemical generation of H 2 O 2. Zhihua Chen, Shucheng Chen, Samira Siahrostami, Pongkarn Chakthranont, Christopher Hahn, Dennis Nordlund, Sokaras Dimosthenis, Jens K. Nørskov, Zhenan Bao, Thomas F. Jaramillo . Reaction Chemistry & Engineering . 2017. Nickel-silver alloy electrocatalysts for hydrogen evolution and oxidation in an alkaline electrolyte. Maureen H. Tang, Christopher Hahn, Aidan J. Klobuchar, Jia Wei Desmond Ng, Jess Wellendorff, Thomas Bligaard, Thomas F. Jaramillo . Physical Chemistry Chemical Physics , 16 , 19250- 19257 . 2014.