Introducing HY-CAT, a project devoted to finding better catalysts to spur a CO2 circular economy
The world’s current dependence on fossil fuels requires us to capture and store the CO2 human civilisation produces, to prevent unacceptable CO2 levels in the Earth’s atmosphere. However, there are also limits to CO2 storage. What if excess CO2 could be converted into useful chemicals instead, thus creating, in effect, a CO2 circular economy? The HY-CAT (Multifunctional Hybrid Platforms based on Colloidal Nanocrystals to Advance CO2 Conversion Studies) research team, based at the Swiss Federal Institute of Technology, Lausanne, is working to synthesise hybrid materials comprised of atomically well-defined CO2 sorbents, which are thin, porous layers of the so-called metal-organic frameworks (MOFs), and nanocrystalline catalysts intimately bound in a single integrated system. They will use three different classes of hybrids, each characterised by one specific absorption/preactivation mechanism, to make a detailed investigation of the effect of mechanisms on the catalyst activity. Such a methodical approach enables the team to compare structure and activity, determining the design principles upon which better catalysts can be made. HY-CAT has already reached some notable milestones. This includes learning how to synthesise hybrid electrocatalysts, including silver nanocrystals embedded in MOFs. They found that MOFs make the nanoparticles more selective, thus making them more energetically favourable as a reaction channel, for CO2 reduction and more stable towards aggregation during catalysis. They have also successfully developed an approach to form a copper/ceria oxide (Cu/CeOx) system, finding that such a combination of nanoparticles also makes copper more selective towards converting CO2 to methane. From a commercial standpoint, HY-CAT has also designed and built a state-of-the-art electrochemical cell that is fed by gas instead of aqueous electrolyte. This device makes it possible to test the catalysts under commercially relevant conditions, a crucial step for making real progress towards true sustainability. HY-CAT began in January 2017 and will run until June 2022.
Keywords
HY-CAT, CO2, catalyst, methane, nanocrystalline, electrocatalysts, silver, copper