Researchers at the University of Cambridge have successfully developed an integrated device capable of harnessing sunlight to convert carbon dioxide captured from the air into hydrogen and carbon monoxide. Notably, this groundbreaking process is directly coupled with the utilization of captured carbon dioxide in a solar-powered system, all within a single device.
Using a standard amine/hydroxide solution under ambient conditions, carbon dioxide was effectively captured from simulated flue gas or air. The device’s perovskite-based photocathode, equipped with a cobalt-phthalocyanine catalyst, facilitated the generation of syngas, comprising carbon monoxide and hydrogen, from the captured carbon dioxide.
Moreover, at the dark anode, a copper-palladium alloy catalyst enabled the oxidation of ethylene glycol derived from discarded plastic waste, specifically polyethylene terephthalate, resulting in the production of glycolic acid. This innovative system taps into atmospheric carbon dioxide as the carbon source, while discarded plastic waste serves as the electron donor, and sunlight remains the sole energy input.
Traditionally, water oxidation has been used as a conventional anode reaction; however, this novel process relies solely on plastic waste oxidation, which is a less thermodynamically demanding and more efficient process. According to Motiar Rahaman, a senior postdoc in the Cambridge lab, this integrated approach represents the first-ever demonstration of connecting direct air capture of carbon dioxide with its immediate utilization in a solar-powered process, all within a single device.