Electrochemical CO2 Reduction Catalysis and Device Integration
Artificial photosynthesis provides the opportunity to store renewable sources of energy (solar, wind, hydro) in the form of chemical bonds by electrochemically converting carbon dioxide into valuable fuels and chemicals. Advancing these technologies to the point they are techno-economically viable will provide means to close the carbon cycle by preparing carbon-neutral or even (ideally) carbon-negative fuels and chemicals. The Higgins group focuses on the development of nanostructured CO2 reduction catalysts with carefully tuned compositions and structures to gain a fundamental understanding of this important electrochemical reaction. Furthermore, catalyst integration into working artificial photosynthesis prototype devices to achieve high conversion rates, energy efficiency and product efficiency is an ongoing effort.
Supercapacitors are energy storage devices that have attracted much attention due to owning outstanding properties like high power density and rapid charge and discharge cycles. Supercapacitors use two main mechanisms to storge charge: I) electrical double layer II) pseudocapacitance. These devices can be employed for various applications, such as the automotive industry. Their major drawback is low energy density that needs to be resolved. Therefore, in the Higgins group, we focus on
Synthesis of scalable, cost-effective graphene-based supercapacitor materials based on the guidance of industrial partners
Advanced characterization of synthesized graphene materials to understand the underlying mechanism by the correlation with electrochemical performance
Electrochemical performance evaluation of graphene-based materials to ensure energy storage capacity and Coulombic efficiency (i.e., stability during charge/discharge cycles)
Zinc ion batteries
Zinc-ion batteries are an emerging type of electrochemical energy storage technology targeted for stationary applications at the grid-level. Offering many advantages over current energy storage solutions (i.e., lithium-ion batteries) including improved safety, use of inexpensive raw materials, and little to no environmental impact. ZIBs may play an important role in decarbonizing the grid and enabling use of variable renewable energy sources. The Higgins group is mainly focused on improving the performance (i.e., capacity, lifetime) of ZIBs through the design and development of new positive electrode materials, with an emphasis on the scale-up and commercialization potential of the technology.
Electrochemical conversion of glycerol
Glycerol, side product of the biodiesel production, can be found in huge amount with low cost. The increase in biodiesel production has led to an overproduction of glycerol. The excess of glycerol has not only reduced the efficiency of biodiesel production by increasing the cost of storage and disposal but also has become an environmental problem. In this context, electrochemical conversion of glycerol is an environmentally friendly method and increases the economic value of glycerol by producing value-added chemicals. Valorization of glycerol is of great importance in terms of providing the opportunity to support the continuance of biodiesel production. The Higgins group aims to develop stable and active catalyst for glycerol electrooxidation reaction (GOR).
Operando / in situ characterization of electrocatalyst and electrode materials
Understanding the role that the physical and chemical properties of nanomaterial catalysts and electrode structures have on performance is crucial for the discovery/design of new materials. Ex situ characterization of materials is not always reflective of the material properties during operation. Therefore, our group uses a variety of in situ / operando microscopic and spectroscopic approaches to gain an accurate understanding of the important factors that govern catalytic activity, selectivity and stability.
Fuel Cell Catalysis (Oxygen Reduction Reaction)
Low temperature fuel cells hold promise for enabling a sustainable transport sector that operates off of zero-emissions hydrogen produced by renewable means (i.e., electrolysis). Current challenges hindering widespread deployment of fuel cells are cost and stability challenges arising from the Pt-based oxygen reduction reaction (ORR) catalysts used at the cathode. It is essential to reduce Pt contents by achieving catalyst activity improvements while simultaneously improving the long-term operational stability. The Higgins group focuses on the development of low-Pt or Pt-group metal free (PGM-free) catalysts and their integration into operational fuel cells.
Electrochemical Water Splitting Catalysts
Electrochemical water splitting using renewable electricity (solar, wind, hydro) provides sustainable means for producing hydrogen. Hydrogen has many industrial uses, including fertilizer (ammonia) production, petrochemical processes and as a carbon-free fuel. Particularly, hydrogen fuel cells have the potential to transform the transportation sector. Operating on hydrogen produced renewably, fuel cell powered automobiles have the potential to reduce greenhouse gas emissions by as much as 90% in comparison to conventional internal combustion vehicles. The Higgins group focuses on the development of inexpensive nanostructured catalysts with high activity and stability for the oxidative oxygen evolution reaction (OER) or reductive hydrogen evolution reaction (HER).