Overview
Interfacial reactions are critical in energy conversion and storage technologies ranging from electrolyzers, to fuel cells and batteries. These reactions often involve multiple electron transfer steps and chemical bond formations, complex reaction pathways, and mass transport across two/three phases. The culmination of these characteristics can lead to sluggish reaction kinetics and poor product selectivity. In facilitating interfacial reactions, (electro)catalysts are vital for activating chemical bonds, stabilizing reaction intermediates, and steering reaction selectivity.
Our research program seeks to:
Understand chemical reaction at solid surfaces
Accelerate (electro)catalysts discovery and development
Engineer devices and processes for chemical transformations
Electrochemical CO2 reduction (eCO2R)
Converting CO2 into chemicals and fuels using renewable electricity is an attractive strategy towards carbon capture and utilization. Electrochemistry allows one to generate an intense local electric field gradient that facilitates CO2 activation while maintaining an overall mild reaction conditions. Our research focuses on developing efficient, selective, and stable electrocatalysts for eCO2R. Using powerful spectroscopic and imaging techniques, we study the correlations between catalyst selectivity and its composition and structure. We also integrate eCO2R electrocatalysts with prototype electrolyzers to achieve high energy efficiency and carbon utilization at industrially relevant rates.
Oxygen electrochemistry
Oxygen electrochemistry has great technological importance. Oxygen reduction and oxygen evolution reactions (ORR, OER) dictate the efficiency, lifetime, and costs of fuel cells, metal-air batteries, and water electrolyzers. A primary challenge in oxygen electrochemistry is to overcome the sluggish reaction kinetics and maintaining stable voltages without the use of precious metals such as platinum and iridium. Rational design of non-precious metal electrocatalysts for ORR and OER requires fundamental understanding of the ORR and OER mechanisms as well as knowledge of catalyst activation, transformation, and deactivation during catalysis. Our research in oxygen electrochemistry focuses on identifying key structural motifs for catalyst activity and their poisoning/destruction at device failure.
Biomass valorization
Biomass is an alternative source of organic carbon that can be produced at scale from renewable sources. Electrochemical processes are attractive for biomass conversion due to the ability to integrate renewable energy for chemical transformation at low temperature and pressure. Also, a wide range of oxidation and reduction half-reactions can be paired in an electrochemical scheme making this process highly versatile. Our research focuses on the development of novel electrocatalysts and processes that will accelerate accelerate carbon-negative biomass valorization by electrochemistry.