Ïã¸ÛÁùºÏ²Ê

All our congratulations toÌýHaiyue YuÌýfor officially becoming Dr Yu on 28 October 2021, based on his PhD thesis in the NICE Group, in theÌýÏã¸ÛÁùºÏ²Ê Centre for Nature Inspired Engineering (CNIE)ÌýandÌýthe Department of Chemical Engineering!

Haiyue’s PhD thesis is titled: "Development of a novel ultra-high vacuum diffusion apparatus for investigating Knudsen diffusion in complex pore channels". He was advised by Professor Marc-Olivier Coppens. Last June, Haiyue was thoroughly examined by Dr Ìý(University of Manchester) andÌýDrÌýFederico GalvaninÌý(Ïã¸ÛÁùºÏ²Ê Chemical Engineering).

The objective of the experimental setup built by Haiyue Yu is to investigate geometrical effects on Knudsen diffusion in nanopores by "scaling up" to macroscopic scales, namely working under high vacuum to achieve the Knudsen regime (mean free path much larger than the channel diameter). This has been extraordinarily challenging to put to practice, requiring Haiyue to combine technical engineering acumen with fundamental understanding of vacuum science, physical chemistry, and materials under vacuum (as molecules tend to adsorb when you least want them to, for a long time...!). He translated that into practice, whilst understanding the chemical engineering context. Haiyue used 3D printing to generate fractal pore shapes based on computational design.Ìý

We also thank Sander BaltussenÌý(now System Engineer at ASML) who has worked on this topic with Marc-Olivier at the TU Delft (the Netherlands) in the past, and who shared helpful experience with Haiyue. At the Ïã¸ÛÁùºÏ²Ê CNIE, we could return to this topic thanks to technical progress, but it remains very challenging even today to ensure proper control over the vacuum and materials properties. Constraints imposed by theÌýCovid-19 pandemic have made it necessary to cut short some experiments, however Haiyue made sure to convincingly test the premise of the instrument and the approach, and to combine his experiments with computations for validation, comparing with work by former postdoc Dr Kourosh Malek and analytical calculations by Marc-Olivier Coppens, going back >25 years.Ìý A century-old topic, and yet the significant effects of short pore lengths and surface roughness in porous materials used for catalysis and separations are, still, almost always ignored even today, as discussed in a

Dr Yu’s research is now continued by PhD student Maria Mourkou, thanks to sponsorship by Synfuels China. Haiyue also worked on titanosilicate catalysts, a topic on which he co-authored two journal publications in the Journal of Materials Science, as proper control of molecular transport is very important in heterogeneous catalysis. Haiyue was also a committed demonstrator for the NICE module.

We wish Dr Yu all the best for the future!