Innovative catalyst achieves continuous CO2 conversion regardless of weather conditions
by Simon Mansfield
Sydney, Australia (SPX) Jan 01, 2024
In a significant advancement in the field of sustainable technology, a joint team from the Institute of Earth Environment, Chinese Academy of Sciences, University of Science and Technology of China, Institute of Atmospheric Physics, Chinese Academy of Sciences, and Shaanxi Normal University has unveiled a novel approach to carbon dioxide (CO2) conversion that operates effectively irrespective of sunlight availability. This research, published in the National Science Review, presents a groundbreaking method to decouple light and dark reactions in the photocatalytic process, drawing inspiration from natural photosynthesis.
The research article, entitled “Sustainable all-weather CO2 utilization by mimicking natural photosynthesis in a single material,” demonstrates a pioneering concept in artificial photocatalysis. Traditionally, converting CO2 into compounds like CO, CH4, and CH3OH relies heavily on the availability of sunlight, with photogenerated electrons having a lifespan ranging from sub-picoseconds to a few seconds. This short lifespan leads to the immediate halt of the photocatalytic reaction when illumination ceases, posing a considerable challenge for consistent solar-driven CO2 conversion due to varying daylight durations and weather conditions.
Addressing this challenge, the team developed a model catalyst comprising Pt-loaded hexagonal-WO3 (h-WO3), aimed at storing photogenerated electrons and hydrogen atoms under light and facilitating CO2 conversion in the dark. The unique properties of the h-WO3 carrier, notably its ability to switch between W6+/W5+ valence states and its hexagonal tunnel structures, in conjunction with Pt’s proficiency in water splitting and transferring hydrogen atoms onto the h-WO3 surface, are pivotal in achieving this decoupling of light and dark reactions.
In a remarkable demonstration of this technology, when exposed to simulated sunlight for 10 minutes, the catalyst enabled the conversion of CO2 to CH4 in the dark for an extended period of 10 days. This indicates the potential for a single material to promote CO2 conversion in all-weather conditions. Further validating their concept, the researchers conducted continuous 15-day experiments using natural light in outdoor experimental equipment. The results showed that the CO2 reduction process remained effective even at night and during rainy days, thus overcoming the limitations of sunlight-dependent systems.
By successfully separating the light and dark reactions in the CO2 conversion process, this new technology makes solar-driven CO2 utilization independent of the uncertainties related to sunlight availability. This development is not just a step forward in the realm of sustainable technology but also holds promise for addressing the energy crisis and achieving net CO2 emission reduction. The ability to efficiently utilize CO2, a major greenhouse gas, in various weather conditions, opens up new avenues for sustainable energy and environmental management.