High-purity carbon monoxide production via photothermal formic acid decomposition over fluorite ZrO2

Abstract

High-purity carbon monoxide (CO), crucial for various high-tech industries, requires complex purification and further energy input. Here we show that pure fluorite ZrO₂ can produce clean CO without purification by driving formic acid dehydration and completely shutting off the formic acid dehydrogenation pathway. An explosion method is developed for synthesizing pristine fluorite ZrO₂ nanosheets that achieve a pure CO production rate of 55 mmol g⁻¹ h⁻¹ at 250 °C. Integrated with a homemade photothermal reactor, the fluorite ZrO₂ nanosheets show a pure CO productivity of 83 mmol g⁻¹ h⁻¹ under 0.5 sun irradiation and a photochemical energy conversion efficiency of 12.3%. Moreover, this system generates over 1,538 l m⁻² of pure CO per day under outdoor sunlight irradiation. This work charts a promising course for purification-free pure CO generation without secondary energy input.