(6bm) Bridging Concepts between Electrochemically and Thermally Activated Catalytic Reactions | AIChE

(6bm) Bridging Concepts between Electrochemically and Thermally Activated Catalytic Reactions

Authors 

Resasco, J. - Presenter, University of California, Santa Barbara
Research Interests:

Past and Current Research:

At the atomic level, catalytic reactions involve the making and breaking of chemical bonds between reacting molecules and active sites. This has led to the development of a framework for understanding heterogeneous catalysis in terms of active site-adsorbate interactions. However, as our ability to characterize the complex nature of active sites advances, it has become clear that secondary interactions, resulting from the presence of the supports onto which active sites are dispersed and the solvating media in which the reaction occurs, also strongly impact the reaction energetics. Appreciation of the full complexity of active sites is therefore essential for a full description of a catalytic process, and once understood, can provide additional tools for designing catalysts. Throughout my Ph.D. and postdoc, I have sought to understand the impact of these secondary effects on both electrochemical and thermally activated catalytic reactions.

During my Ph.D. research at the University of California, Berkley with Prof. Alexis Bell, I studied the effect of electrolyte ions on the electrochemical reduction of carbon dioxide. The composition of the electrolyte in which electrocatalysts are tested has been observed to influence reactivity; however, detailed understanding of these effects is still lacking. Through a combination of experimental and theoretical studies, we elucidated the effects of electrolyte cation and anion identity on the activity and selectivity of metal catalysts for this reaction. Kinetic studies, supported by density functional theory calculations, demonstrated that solvated cations interact electrostatically with adsorbed species, having a preferential effect on intermediates with high polarity. Thus, cations in solution act as a built-in promoter with a function analogous to alkali metal promoters for gas phase reactions. Anions can also affect CO2 reduction rates, acting both as a buffer and a proton source, increasing rates of hydrogenation reactions.

Currently, I am working as a postdoc at the University of California, Santa Barbara with Prof. Phillip Christopher, understanding analogous effects of how the coordination of atomically dispersed platinum catalysts to oxide supports influences activity. Through a combination of atomic level and sample averaged in-situ characterization, we demonstrated that the local coordination of the metal to the support determines the ability of the surface site to form additional bonds with adsorbates, altering reactivity.

Future research:

Significant environmental issues associated with the use of fossil fuels, along with advances in technologies to generate renewable electricity have made it likely that future energetic inputs to drive chemical transformations will be electrical in addition to thermal. However, the use of electrocatalytic processes for sustainable fuel and chemical production requires scientific breakthroughs in the design of catalysts and reaction systems to drive these reactions. Understanding the fundamental concepts that govern reactivity in these systems can enable their rational design and facilitate these breakthroughs. In my research, I plan to establish parallels between well studied thermal catalytic reactions and new electrocatalytic processes to provide design rules for catalyst design and highlight what unique opportunities the electrochemical system provides. I plan to explore the diversity of chemical transformations possible by electrochemical processes, beyond the conversion of small molecules such as water and carbon dioxide. For instance, I plan to study electrochemical processing of biomass derived platform molecules to form fuel additives and polymer precursors, and selective oxidations with application to the conversion of natural gas feedstocks.

Teaching Interests:

I have always had a passion for teaching, both in the classroom and laboratory, and teaching is a major driver in my decision to pursue an academic career. My goal in teaching is to develop a student’s deep understanding of a few core Chemical Engineering concepts and use them as a guide to approach any problem they are faced with. As an undergraduate I worked as a Chevron Philips Scholar-Mentor for Chemical Engineering Fundamentals. In graduate school, I served as a graduate student instructor (GSI) for undergraduate Thermodynamics and graduate Kinetics and Reaction Engineering courses. I was awarded the departmental Outstanding GSI award for the graduate Kinetics Course. Based on these enjoyable and instructive experiences, I independently developed and taught an elective course Fundamentals of Electrocatalysis. As a faculty member, I am excited to teach any of the core courses of Chemical Engineering, particularly courses in Kinetics and Reaction Engineering. I am also eager to develop new courses such as Electrochemical Engineering, or an introductory course on current and emerging energy transformations. These courses would aim to expose students to interesting applications of the foundational principles of thermodynamics, kinetics, and transport phenomena. In the laboratory, I have served as a mentor to undergraduate and junior graduate students. Serving as a mentor and aiding in the development of students in research will be an important focus throughout my career as a faculty member.