Mesoporous oxide nanoreactors for gas-phase CO2 electroreduction and mixed homogeneous/heterogeneous electrocatalysis

Global warming is one of the biggest challenges that our society is facing today. True circularity of carbon is needed to fulfil the increasing demand for energy while reducing greenhouse gas emissions. The electrochemical reduction of CO₂ back to valuable molecules for chemical industry or as e-fuels are examples of how the carbon cycle can be restored. At imec we are using nanotechnology to improve the efficiency of electrochemical reactions in electrolyzers and fuel cells. We have developed a few micron thick nanomesh electrode with extremely large surface area which significantly lowers the reaction overpotential, making the electrocatalytic reaction more energy efficient [1]. The nanomesh electrode is currently being upscaled for applications in hydrogen electrolyzers [2]. Today, we are further developing this technology towards CO₂ electroreduction to products like forming gas and methanol. We are developing gas-diffusion-electrodes (GDE) with high throughput and a potential to convert CO2 directly from the waste of flue gas and eventually even from the air. We are developing smart catalyst approaches to steer the electrocatalytic reaction path towards the desired products and yields. We are working on sorbent materials to augment CO2 supply to the catalyst in the gas diffusion electrodes. We are using modeling to understand the mass transport and confinement effects in these nanoporous gas electrodes. Nanoconfinement of the electrochemical environment and electrolyte management in the electrodes are key factors for control of the electrocatalytic reaction and stability over time. In this regard, we have defined a PhD topic to study and control the nanoconfinement effect using nanoreactors in mesoporous oxides. Using mesoporous thin-films on electrocatalyst layers, we will study the effect of nanoconfinement on both the heterogenous surface reaction as for as on the homogeneous solution environment and the effect of redox mediators. You will learn and develop thin-film coating of mesoporous oxides and nanocomposites on both planar and high surface areas nanomesh electrodes. Next to the fabrication of the 3D-networks the student will develop a fundamental understanding of mass transport and confinement effects inside these complex nanostructured electrodes using electrochemical analysis techniques. With this knowledge the final goal is to develop a high-throughput CO₂-electrolyzer that directly operates from the gas-phase making use of the high surface area of the nanomesh. Different integration strategies of the nanomesh electrodes and a solid electrolyte will be investigated to obtain high efficiencies towards the desired CO₂RR products. 

[1] https://www.imec-int.com/en/press/100-fold-current-density-enhancement-puts-imecs-nanomesh-electrodes-pole-position-high

[2] https://www.imec-int.com/en/press/flemish-expertise-centres-join-forces-industry-push-green-hydrogen-production-forward

[3] https://www.imec-int.com/en/articles/novel-nanomaterial-promises-improvements-in-batteries-and-many-more-sustainable-applications