PORTFOLIO

High concentration of atmospheric CO2 and energy crisis are two of the major challenges facing our human beings nowadays. One promising technology to tackle these challenges is the solar-driven conversion of CO2 to fuels and chemicals, known as artificial photosynthesis. In this project, we will develop systems which integrate photovoltaics, electrolyzers and fermenters together to convert CO2 to alcohol fuels with solar radiation as the only energy input. Perovskites photovoltaics will be employed to produce renewable electricity that is used for the generation of syngas via electrolysis. The syngas will be introduced to the fermenters containing microorganism such as C. autoethanogenum and C. kluyveri to produce alcohol fuels. This fermentation process also serves as an effective separation technique by converting gas products to liquid fuels. The entire system is expected to have remarkable energy efficiency, high production rate and robustness. We expect to achieve 10% solar energy to chemical energy efficiency for the conversion of CO2 to alcohol fuels. At the end of the project, the technology readiness level (TRL) is expected to be at 4-5 and we will explore the potential for upscaling towards TW-scale by 2050.

Solar-driven CO2 reduction to alcohols have been studied in photocatalysis and photo-electrochemistry. However, the energetic efficiency is far from satisfactory. Here, we employ microorganism to convert syngas to alcohol products to circumvent the energy barrier required for the direct reduction of CO2 to alcohol fuels. This innovative tandem electro-bio method will enable exceptionally high energetic efficiency. Moreover, our system will be only dependent on earth abundant materials and will employ the new-generation photovoltaics based on perovskites. These new aspects will not only push the efficiency to a new level, but also bring chemists and microbiologist together to address our concerns on energy crisis and climate change.

We have designed efficient electrocatalysts for the respective synthesis of hydrogen (H2) and carbon monoxide (CO) from water splitting and carbon dioxide (CO2) reduction. After optimizing key components in the electrolyzers, remarkable electricity-to-fuel energy conversion efficiencies for H2 and CO were achieved on newly-developed catalysts. Additionally, by engineering the configuration of organic-inorganic halide perovskite solar cells, we have achieved an efficient solar-to-electricity conversion which were further used to power water splitting and CO2 reduction. The combined photovoltaic-electrolyzer systems illuminated under standard AM 1.5G sunlight, without applying any external bias, delivered a remarkable conversion efficiency of 12.9% for solar-to-H2 and a new record of 19.7% for solar-to-CO conversion, respectively. Research activities on microorganism cultivation are now still ongoing to achieve final alcohols generation by feeding produced syngas and using renewable solar energy as the only input power.

Nature Communications, 2022, 13, 5898