Dual-function materials used for CO2 capture and conversion create value-added products
By Dr. Ana C. Alba-Rubio
Climate change is not an opinion; it is a real issue supported by strong scientific evidences. Even when we are dangerously approaching the so-called “point of no return,” surprisingly, there are still few actions being taken. It seems we forgot how good living on a healthy planet was, and now we do not care about leaving a sick Earth to future generations.
Carbon dioxide (CO2), a major air pollutant released into the atmosphere by the combustion of carbonaceous fuels, is one of the primary causes of global warming. It is, by far, one of the biggest sources of waste produced by human activities, with an annual global emission of 37.1 billion metric tons in 2018. The CO2 concentration in the atmosphere today is 415 ppm. I force myself to share that number often, so people can realize this is something that is happening much faster than we thought. Indeed, extrapolations of emissions trends suggest that even with strong efforts to limit emissions, CO2 concentrations in the atmosphere will rise beyond 450 ppm before we reach the middle of this century, with risk of catastrophic impacts.
With growing population size and oil consumption, it will be difficult to maintain our current quality of life. Therefore, future strategies to combat global warming must focus on energy security while reducing greenhouse gas emissions. The solution seems clear: environmental awareness, reforestation, transition from fossil fuels towards renewable sources, and active removal and control of CO2 emissions.
CO2 capture and sequestration, together with CO2 capture and catalytic conversion to fuels and materials, might help to mitigate the greenhouse effect. However, CO2 capture and conversion at the exhaust of combustion (e.g. flue gas at fuel oil, natural gas, or coal power plants) is more attractive, not only because industries could economically benefit from a waste, but also because that would reduce the amount of gases emitted to the atmosphere.
Dual-function materials, which are capable of capturing and converting CO2, are gaining attention, since they might eliminate the energy requirement, corrosion, and transportation issues associated with capture and sequestration. Our research group has recently been awarded a grant from the National Science Foundation through the Faculty Early Career Development Program to develop this type of material.
Our lab at the University of Toledo focuses on the rational design and synthesis of heterogeneous catalysts for sustainable processes. Catalysts are substances that are added to chemical reactions to make them faster – or even possible. This new project aims to create dual-function materials able to concentrate and capture CO2 at the surface of the catalyst for an effective conversion to methanol and higher alcohols, which are important commodity chemicals.
These materials could be placed at the top of industrial smokestacks for in situ capture and conversion of CO2 into alcohols, which could be fed into a fuel cell to produce electricity to power the plant. This arises as an example of circular economy to reduce greenhouse gas emissions. I believe circular economy and improved utilization and reutilization of resources is essential to protect our environment, society, and economy
at large. The current model of trying to use all the resources we have while they last is no longer sustainable, and carbon taxes need to be imposed to create awareness of our carbon footprint.
When industries recognize CO2 as a valuable product, they will try to make a profit of it, and that will be the turning point in our fight against climate change. At that point, we will be ready to change the destiny of humanity.
Dr. Ana C. Alba-Rubio is an Assistant Professor in the Department of Chemical Engineering at the University of Toledo. Her research focuses on the rational design of heterogeneous catalysts to provide fuels and materials sustainably.