Cuprous Single Sites in Metal-Organic Frameworks for Fuel Synthesis by Electrocatalytic CO2 Reduction

Climate change is a tangible reality, while there are increasing evidence and scientific consensus supporting its man-made origin. It is linked to the increasing greenhouse gas CO2 levels in the atmosphere, a direct consequence of our industrial and personal activities. While a lot of progress has been made in electrifying our homes, transport and the industry using renewable energy sources, this approach will never be able to fully provide for all our energy needs based on the fact that renewables cannot supply a constant amount of electricity (e.g. it is not always sunny/windy), and electricity use is not always practical (e.g. in remote communities, on ships and planes). In this work we will apply materials that can directly transform CO2 into liquid fuel, thereby addressing both the energy and climate crises. We will use an innovative type of materials based on copper, which has recently shown promise to this aim. The outcome will be a new and affordable technology that can transform this harmful waste (CO2) into something valuable and useful.

In a bid to reduce atmospheric CO2 levels while converting it into useful chemicals (synthetic fuels methane and methanol), the project undertakes the development of new advanced materials with accurately designed, abundant, and accessible electrochemically active sites. Albeit there is a tremendous body of work into electrocatalytic CO2 reduction, several competing products, high process energy demand, and materials costs remain roadblocks for large-scale applications. Our approach to overcoming the above challenges is the development and assessment of a new family of 3-dimensional metal-organic frameworks based on copper(i) centres, coordinated to two heterocyclic nitrogen and two carboxylic oxygen atoms. Such moieties have recently been suggested as active and selective in CH4/CH3OH production, which are both promising synthetic fuels offering carbon-neutral alternatives of fossil fuels, without a need for infrastructural changes. In addition, MOFs are highly porous and uniform, thereby allowing for a great concentration of accessible redox sites. We will employ a combined effort of materials design and performance testing both in the liquid- and gas phases, exploring lower- and higher risk approaches, respectively. It should be noted that MOFs have particularly high capacity for local CO2 densification, which is promising for gas-phase processes. The structural and compositional evolution of species will be explored using state-of-the-art spectroscopic and scattering techniques, which, combined with theoretical modelling, will enable us to unravel the relevant reaction mechanisms for selected electrocatalysts. This effort will help us understand the requirements for the advanced materials to perform well in the electrocatalytic conversion of waste CO2 into value-added synthetic fuels methane and methanol, and thus to optimise performance. Such approach will greatly contribute to the green energy transition offering a reliable alternative for energy storage.