Special Seminar-Teaching Old Electrocatalysts New Tricks: Merging Concepts from Thermal Catalysis
Friday, March 17, 2023
11:00 a.m.
Room 2108 Chemical and Nuclear Engineering Building
For More Information:
Emmanuel Duh
301 405 1935
eduh@umd.edu

Title: Teaching Old Electrocatalysts New Tricks: Merging Concepts from Thermal Catalysis  and Molecular Synthesis

Decarbonizing the energy and chemical industries motivates the development of new  catalytic technologies that use renewable energy inputs, alternative feedstocks, and spatially  distributed production modalities. In this context, electrocatalysts are tasked with producing  fuels, chemicals, and energy by mechanisms that fundamentally differ from those of  electrolyzer and fuel cell technologies, and the thermocatalytic technologies of incumbent  petrochemical processes. In this presentation I will show how concepts from thermal and  molecular catalysis can stimulate new approaches for the synthesis and application of a class  of heterogeneous electrocatalysts known as M-N-Cs, or metals incorporated into nitrogen doped carbon. M-N-Cs (e.g., M = Fe, Co)  catalyze electrochemical reduction of O2, such as in fuel cells, and catalyze  thermochemical reduction of O2 using hydroquinone (HQ) as the source of  reducing equivalents. Kinetic studies  reveal an unexpected mechanism for HQ mediated O2 reduction through a direct  chemical pathway facilitated by a catalyst  microenvironment modified by adsorbed HQ species. This alternative mechanism  circumvents the rate–potential  relationship observed for electrocatalytic O2 reduction, opening new opportunities  to design fuel cell systems that reduce O2 with higher energy efficiency (i.e., lower overpotential). In a complementary effort, Fe-N-C  heterogeneous catalysts were prepared to contain atomically dispersed metal active sites by  adapting synthetic strategies used to metalate molecular macrocycle catalysts under solution phase conditions and milder temperatures (150 °C) than those of conventional pyrolysis based preparation routes (600–1100 °C). These well-defined Fe-N-C catalysts directly  implicate atomically dispersed FeNx moieties as the active sites for aerobic oxidation  reactions. These studies show how thermochemical and molecular concepts can be leveraged  to understand and improve the structure and function of electrocatalysts that are critical for  next-generation energy and chemical conversion processes.

Bio. Jason S. Bates received his B.S. in Chemical Engineering at  
the University of Kansas in 2014 and a Ph.D. in Chemical  
Engineering at Purdue University in 2019, under the supervision  
of Rajamani Gounder. He is currently an NIH postdoctoral  
fellow at the University of Wisconsin–Madison in the  
Department of Chemistry, under the supervision of Shannon S.  
Stahl. His research explores the fundamentals of heterogeneous  
(electro)catalysis in areas relevant to decarbonization of the  
energy and chemical industries.

This Event is For: Graduate • Undergraduate • Post-Docs