The CO2 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 CO2 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 CO2 concentration in air, the thermodynamic stability of CO2 (and its capture products), the high O2 content (21%) in air (which often interferes with catalytic CO2 valorization), and the presence of variable moisture levels. This perspective explores different concepts and emerging technologies for the solar-powered conversion of atmospheric CO2 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.
Kar et al. (Wed,) studied this question.