University of Groningen
Synthesis of enhanced catalytic materials in supercritical CO2
Tao, Yehan
DOI:
10.33612/diss.125336968
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Publication date: 2020
Link to publication in University of Groningen/UMCG research database
Citation for published version (APA):
Tao, Y. (2020). Synthesis of enhanced catalytic materials in supercritical CO2. University of Groningen. https://doi.org/10.33612/diss.125336968
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Propositions Accompanying the thesis
Synthesis of Enhanced Catalytic Materials in Supercritical CO2
Yehan Tao
1. Applying supercritical CO2 as reaction medium provides a strategy for in-situ control of the
formation of nanomaterials, which can be combined with its application as drying agent to create high-surface area porous nanomaterials.
2. A rational design of both the reactor and the synthetic procedure is very important for tuning the final structural and physicochemical properties of a material. (Chapter 2)
3. The degree of decomposition of H2O2 in the presence of a catalyst and the related risk of
explosion should be evaluated before defining it as “green” oxidant. (Chapter 2 & 3)
4. When evaluating different catalysts, the applied reaction conditions should be sufficiently challenging to allow distinguishing the difference in their activities. (Chapter 3)
5. The use of glucose instead of fructose for the production of 5-HMF does not necessarily give lower 5-HMF yield. (Chapter 4)
6. When analysing pyruvaldehyde by HPLC, it is important to take into account its possible hydrolysis in the presence of a strong BrØnsted acid (sulphuric acid) as mobile phase. (Chapter 4 & 5)
7. When performing the catalytic conversion of glucose to 5-HMF in DMSO at 150 °C, it is arguable whether the activity is derived solely from the catalyst (Scientific report, 2016, 6, 34068), since this reaction can happen spontaneously at elevated temperatures and, also, DMSO alone can catalyse the formation of 5-HMF (Biomass, 1987, 13-67-74).
8. In most research papers about heterogeneous catalysts, the costs for the synthesis and recovery of the catalyst are not discussed.
9. The surface area and loading of active species of a catalyst should be taken into account when comparing the acidity of different catalysts.
10. When using NH3-TPD to analyse the acidity of a material, the NH3 desorption temperature
should not be higher than the thermal treatment temperature of the tested material.
11. Starting a Ph.D. in a relatively new field is not only full of novelty and attraction, but also of challenges and uncertainty.
12. 怕什么真理无穷，进一寸有进一寸的欢喜---胡适。Don’t be afraid of the infinity of truth, joy resides in every step of growth---by Shi Hu.
