Green Chemistry, Energy and Catalysis
In order to support a growing global population and advance quality of life in a way that is sustainable for the planet, rapid development of green chemical processes as well as clean and renewable energy sources as well as energy efficient are essential. These areas are linked by energy conversion (e.g., light to electrical, thermal to electrical, electrical to chemical) and molecular transformations (the creation of bonds and chemical structures) where the control of mechanisms, catalysis and the flow of energy is critical for designing efficient and clean transformations capable of producing critical materials ranging from fuels to pharmaceuticals.
Energy, Catalysis, Chemical Transformations
Energy and chemical transformations are linked by catalysis, which controls efficiency both in terms of energy consumption as well as the nature of the products (including unwanted by-products - waste). A uniting primary theme among the CTRI team is the development of catalysts based on Earth-abundant elements (including main group elements and transition metals) that are engineered with ligands that impart unprecedented catalytic activity and selectivity. By focusing on Earth-abundant elements as well as developing robust and easily synthesised systems, the team ensures that catalysts and the sought-after chemical transformations they are used for are sustainable, inexpensive, and greener.
Dalhousie chemists have established world-leading programs focused on the use of molecular Earth-abundant transition metal catalysts for a diversity of applications. Mark Stradiotto's work on cross-coupling and Laura Turculet's work on hydrofunctionalization are of importance to a range of industrial partners and other commercialization partners. The bourgeoning field of main-group catalysis is well-represented by the high-impact work of the Alex Speed and Saurabh Chitnis, including in the area of hydrofunctionalization chemistry. Active collaborations with computational chemists such as Erin Johnson serve to provide the basis for further development of practical, high-performing homogeneous catalysts. The development of highly efficient catalytic processes that couple redox and/or light-driven processes represents a natural area of synergy involving energy and Green Chemistry.
Peng Zhang works on noble metal nanoparticle catalysis, while Mita Dasog's research focusses on nanostructured catalysts based on nitrides, carbides and diborides, applying these plasmonic nanoparticles for desalination, water treatment, disinfection, and sensing purposes. Michael Freund, works on nanostructured phosphide and oxide catalysts for water splitting, CO2 reduction and nitrogen fixation.
Replacement of established inorganic-based energy storage and conversion systems such as lithium-ion batteries and silicon-based solar cells with inexpensive and more easily produced organic-based systems has the potential to transform the energy landscape. Organic chemistry offers the unique ability to engineer the electronic structure of molecules to control the flow of charge in a wide range of electronic devices that have already reached the consumer market such as organic light emitting Diodes (OLEDs) and organic thin film Transistors (OTFT). It is only a matter of time before organic materials become a central component of energy conversion and storage systems.
Ian Hill and Michael Freund are developing new light-absorbing materials, based on conjugated polymers, while Kimberley Hall, Ghada Koleilat and Ian Hill are working on organic perovskites for the next generation of PV solar cells. Michael Freund, Ghada Koleilat, and Ian Hill have expertise in processing organic materials into sensors. Alison Thompson has expertise in synthesizing novel conjugated molecular systems. Erin Johnson uses organic design to computationally predict material properties.
Supercapacitors bridge the energy capacity performance of electrolytic capacitors and rechargeable batteries are important for applications requiring short burst for high power applications such as airbag deployment and camera flashes. Heather Andreas studies mechanisms of self-discharge, which is a major limitation in this technology; she has recently forged collaborations with the with the growing graphene industry in the region. Michael Freund develops novel porous redox materials that increases the rate of charging and discharging as well as its charge capacity.
Redox flow batteries (RFBs) are one of the key technologies capable to deliver grid-level energy storage. Existing commercial solutions use vanadium and vanadium oxide as a redox couple. Adapting this technology to organic redox systems is a hot topic worldwide. In Ian Hill's research, redox flow batteries are constructed, cycled, and characterized. Degradation pathways are studied using surface science, electrochemical and spectroscopic techniques. Alison Thompson synthesizes new organic redox molecules, paying attention to energy storage capabilities and enhanced stability. The goal is to improve cycle life in low-cost aqueous organic-based systems. Michael Freund develops polymer membranes to precisely control ion exchange between the two electrolyte compartments of an RFB, thus expanding the range of redox systems to choose from and their stability.