Woehl, Taylor J.

Assistant Professor

Department of Chemical and Biomolecular Engineering

A. James Clark School of Engineering

Phone: 
301-405-1704

Statement of energy interests and expertise: 

Prof. Woehl leads the Nanoscale Assembly and Electron Microscopy Group in the Department of Chemical and Biomolecular Engineering. Our energy research interests are in the area of in operando characterization of active catalyst structure and catalyst degradation mechanisms, applied to electrocatalyst nanoparticles for fuel cells and CO2 electroreduction and metal organic frameworks for processing of fine chemicals.  Degradation of catalysts is a costly industrial problem that limits the lifetime of catalysts and often necessitates high loading of expensive precious metal catalysts. Namely, degradation of polymer electrolyte membrane fuel cell (PEMFC) platinum catalysts has limited the widespread implementation of fuel cells in automotive applications. We develop in operando electron microscopy techniques to simultaneously visualize dynamic changes in catalyst structure under working conditions to correlate with reaction data, such as reaction kinetics or electrocatalytic activity.  Degradation depends on nanomaterial structure across numerous length scales, ranging from atomic scale surface faceting and defects, to single particle shape and size, to mesoscale properties such as particle size distribution and interparticle separation. The overall goal of our research is twofold, we seek to (1) develop fundamental structure-stability relationships that will allow for engineering of resilient catalysts and (2) reveal the active working structure of catalysts to fundamentally understand their mechanism of action.

Our areas of expertise are in situ transmission electron microscopy characterization and nucleation, growth, and assembly phenomena.  At the most fundamental level, catalyst degradation is a combination of nucleation, growth, and aggregation processes. We seek to develop in situ electron microscopy techniques to differentiate the various fundamental processes during catalyst degradation to inform engineering of more resilient catalysts that retain their activity longer.