Molecular hybrid photocatalysts for selective solar H2 and material generation from real life wastes
Lead Research Organisation:
University of Cambridge
Department Name: Chemistry
Abstract
Solar waste photoreforming is a process that generates valuable H2 fuel and chemicals from discarded waste and water using abundant sunlight, providing solutions to many global challenges including waste management, clean fuel generation, and material production. Despite the potential, current state-of-the-art photoreforming processes suffer from major deficiencies including the use of highly basic medium and nonselective product generation that preclude their large-scale implementation. The "Waste2Fuel" proposal seeks to address these deficiencies by employing hybrid photocatalysts, with molecular oxidation catalysts anchored onto photocatalyst surfaces, to carry out selective waste photoreforming under benign conditions. Inspiration to such an approach comes from the recent success in selective CO2 photoreduction with similar hybrid strategy. Among different objectives, molecular catalysts will be first immobilized onto anodes by covalent bond, and conditions will be optimized to obtain selective electrochemical waste oxidation under aqueous conditions by surface-bound catalysts. The molecular catalysts will then be grafted onto photocatalysts to get hybrid photoanodes, which will be subsequently employed for selective solar waste photoreforming. We surmise that during photoreforming, initial hole transfer from photocatalyst to the anchored molecular catalyst will take place, with the latter oxidizing waste substrates in turn, giving high efficiency and product selectivity as is generally observed with molecular complexes. Our final objective is to develop a scalable 10.10 cm2 panel with surface deposited hybrid catalyst for large-scale solar photoreforming, demonstrating its applicability. Successful completion of the research would enable commercialization of the waste photoreforming process, contributing towards the sustainable production of fuel and materials, while at the same time, recycling the generating wastes of our society.
Organisations
People |
ORCID iD |
| Erwin Reisner (Principal Investigator) | |
| Sayan Kar (Fellow) |
Publications
Kar S
(2023)
Integrated capture and solar-driven utilization of CO2 from flue gas and air
in Joule
| Description | In the key finding from the award, we showed CO2 capture and conversion from dilute streams such as flue gas and air in a sunlight-driven photoelectrochemical reactor, producing renewable fuels. Further, this process was coupled with the selective upcycling of PET plastics to a value-added chemical glycolic acid, producing additional valuable products as intended in the original proposal. The overall solar-driven reactor thus combines different sustainable transformations in a synergic manner including selective plastic upcycling, carbon capture and CO2-to-green fuel, opening avenues for solar carbon-neutral and carbon-negative technologies. Both liquid phase and gas-phase conversion of air to fuel have been achieved (Joule 2024 and Nature Energy 2025). |
| Exploitation Route | These findings are currently being taken forward in our lab, exploring ways to scale up the system and bring it to a pilot demonstration led by the project team members. Following this award, we are keen on building upon the foundations laid by this research with other UKRI awards. |
| Sectors | Energy Environment |
| URL | https://www.cam.ac.uk/research/news/clean-sustainable-fuels-made-from-thin-air-and-plastic-waste |
| Description | Two of the major waste streams of the twenty-first century are plastics and CO2, causing irreversible environmental damage to our ecosystems. It is thus imperative to reduce these emissions through capture at the point of release while repurposing the captured CO2 and plastics for use and reinserting them back into the economy. Our work has shown for the first time an integrated way to capture CO2 from point sources and air, and further produce renewable fuels from it in a sustainable sunlight-driven manner. Moreover, the whole process benefits from being coupled to plastic upcycled, which is used and converted into a key ingredient in the skincare industry. Thus, the work from this research provides a holistic proof-of-principle demonstration of different sustainability concerns (carbon removal, renewable fuels, plastic management), and is impactful in all these sustainability areas. It was published in a highly reputed journal 'Joule' and was extensively reported in the media, reflecting the impact of this discovery in the current sustainability context. The findings from this award hold promise toward developing a combined solar-driven carbon capture and utilisation technology coupled with waste upgradation, rather than separate and less beneficial carbon capture-storage (CCS) and waste-to-X technologies. |
| Title | Dataset for "Integrated capture and solar-driven utilization of CO2 from flue gas and air" |
| Description | The dataset contains raw data supporting the article 'Integrated Capture and Solar-driven Utilization of CO2 from Flue Gas and Air'. An integrated photoelectrochemical system has been developed for sunlight-driven captured CO2 conversion coupled to waste plastic reforming. The dataset is divided into four key parts: i) Catalyst Characterization: contains SEM-EDX, IR, UV-Vis data, ii) CO2 Capture: contains NMR data, iii) Electrochemistry: contains all electrochemical data, iv) Photo-electrochemistry: contains all photoelectrochemical data. For more details about experimental procedure, instrumentation, and data collection, see the manuscript. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| Impact | This dataset contains data related to 'Integrated Capture and Solar-driven Utilization of CO2 from Flue Gas and Air'. |