Photothermal catalysis using pulsed light

Catalysts are the workhorses of industrial chemistry, accounting for 85% of chemical products, such as artificial fertilizer and precursors for plastics. Temperature is a key control parameter in any catalytic reaction and reactors are typically heated using fossil-fuel derived heat. It would be more energy efficient and sustainable to only apply heat where the chemistry occurs: at the surface of the catalyst. This is possible with light: using optical excitation allows for faster heating and cooling, while giving us wireless and remote spatiotemporal control over heat generation. Especially plasmonic nanoparticles are attractive for this strategy, due to their outstanding ability to convert light to heat on the nanoscale.

We recently predicted that using an (ultra)fast pulsed light source can speed up photothermal catalysis drastically, and can result in a different reaction selectivity compared to continuous wave illumination (CW, e.g. sunlight or LEDs). However, so far there is only very limited experimental evidence for this prediction. The aim of this project is to directly compare the catalytic performance of arrays of plasmonic nanoparticles under CW and pulsed laser excitation in a custom-built photothermal reactor setup, and to find the conditions under which pulsed light outperforms CW. We focus on CO2 hydrogenation and study the energy efficiency and we aim to steer the reaction selectivity towards either methane or carbon monoxide.

The project is supervised by experienced researchers in nanophotonics and plasmonics (Sven Askes & Andrea Baldi) and will be hosted by the PhotoConversion Materials section of the Physics department of the Vrije Universiteit. We are a kind and supportive group of people who are serious about supervision and mentorship, and hope to work with you on this exciting project!