While the stored chemical energy in coal, oil and natural gas has enabled the rapid rise of modern civilization, the burning of these legacy fossil fuels with its accompanying anthropogenic CO2 emissions is occurring at a rate that is outpacing nature’s carbon cycle. The effect of these emissions is now considered by the Intergovernmental Panel on Climate Change  to be high to very high risk and could lead to a rapid and massive upheaval of human society unless a global scale solution to the intertwined effects of fossil fuels, energy security, environmental protection and climate change is found. In this context, a recent modeling research study concluded that most of the world's fossil fuel reserves need to stay in the ground over the period 2010-2050 to not exceed the 2°C warming limit and avoid the risk of dangerous global warming . Clearly, climate change is a complex technological, environmental, societal, economic and political issue without a simple solution.
To address this challenge, the U of T Solar Fuels Cluster, as well as many other talented researchers and top rank groups around the world, are targeting innovative technological solutions that focus on the capture and conversion of CO2 into renewable fuels using sunlight as the energy source, H2O and/or H2 as the co-reactant. This transformative research paradigm treats CO2 as a renewable resource rather than a waste product, turning CO2 from a liability to an asset, thereby providing a chemical platform for developing a carbon-neutral CO2 economy that can enable a sustainable future for humankind. Progress of research in this area is gathering momentum and will probably continue to do so for the foreseeable future.
It is worth commenting that in this endeavor there exist two schools of thought: (i) an aqueous process, which is likened to artificial photosynthesis practiced by the leaf, with more than four decades of research activity aimed at developing laboratory scale mimics and ultimately scale-up and (ii) a gas-phase process, which is more akin to heterogeneous photocatalysis, of a more recent vintage that more closely resembles heterogeneous catalysis practiced by industry. The latter approach is the main focus of attention of the U of T Solar Fuels Cluster.