Solar Air-to-Fuel Technologies for a Circular Carbon Economy

High Resolution Image Download MS PowerPoint Slide The CO 2 present in our atmosphere is a universally available and abundant carbon feedstock, but it exists only in dilute concentrations (currently around 427 ppm). Clean technologies capable of capturing atmospheric CO 2 using direct air capture and directly converting it into synthetic fuels and chemicals using solar energy could pave the way for a circular chemical industry. Challenges in developing such a solar-powered air-to-fuel technology that mimics photosynthesis include the use of the low CO 2 concentration in air, the thermodynamic stability of CO 2 (and its capture products), the high O 2 content (21%) in air (which often interferes with catalytic CO 2 valorization), and the presence of variable moisture levels. This perspective explores different concepts and emerging technologies for the solar-powered conversion of atmospheric CO 2 into fuels and chemicals, examines their scientific principles, considers their scalability, and offers recommendations for future research to support the development of a net-zero circular carbon economy.