ED Sciences Chimiques
Design of heterogeneous catalysts and porous materials for green production of chemicals, biomonomers, and pharmaceuticals
by Sorasak KLINYOD (Institut des Sciences Moléculaires)
The defense will take place at 14h00 - ESE306 Vidyasirimedhi Institute of Science and Technology, School of Energy Science and Engineering, 555 Moo 1 Payupnai, Wangchan, Rayong, 21210, Thailand
in front of the jury composed of
- Alexander KUHN - Professeur des universités - Université de Bordeaux - Directeur de these
- Chularat WATTANAKIT - Associate Professor - Vidyasirimedhi Institute of Science and Technology - CoDirecteur de these
- Günther RUPPRECHTER - Full professor - Technische Universität Wien - Rapporteur
- Christine KRANZ - Full professor - Universität Ulm - Rapporteur
- Emiel HENSEN - Full professor - Eindhoven University of Technology - Examinateur
- Tawan SOOKNOI - Full professor - King Mongkut's Institute of Technology Ladkrabang - Examinateur
In this thesis, the rational design of various porous heterogeneous catalysts is described for the applications of green production of biogenic chemicals and chiral compounds. In a first and very detailed study, isomorphous substitution of tetrahedral Ti(IV) active sites in the different zeolite topologies, including ZSM-35 (FER), ZSM-5, and BEA, has been investigated through a post-synthetic approach. The specific tetrahedral Ti(IV) active species, without interference from non-framework Ti(IV) species, can be successfully incorporated into the titanium-containing BEA (Ti-β) zeolite, unlike in Ti-ZSM-35 and Ti-ZSM-5, eventually enhancing catalytic performances in the epoxidation of methyl oleate (MO) over Ti-β with respect to Ti-ZSM-35 and Ti-ZSM-5 catalysts. Moreover, this thesis also elucidates the strategy for improving the efficiency of the incorporated Ti(IV) active sites present in hierarchical titanium-containing silicalite-1 (HieTS-1) by tuning its Lewis acid strength via the bottom-up approach. A one-pot hydrothermal synthesis involving an additional precursor, NH4F, has been demonstrated to generate three different Ti(IV) active sites with different Lewis acid strength in the order of closed Ti(OSi)4 < open Ti(OSi)3OH < open Ti(OSi)3F. Interestingly, adjusting the portion of each Ti(IV) active site in the HieTS-1 significantly enhances the catalytic activity of MO epoxidation. In a second part, this thesis also extends the scope of heterogeneous catalyst design to electrochemical processes. In this work, the efficiency of nickel nanoparticles (NiNPs) supported on graphene oxide (GO) has been improved by an alkaline treatment under the influence of an applied positive potential. This can significantly alter the low valence state of Ni metal (Ni0) to the high valence state of NiOOH species (Ni3+), thereby enhancing the catalytic activity of electrochemical oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-Furandicarboxylic acid (FDCA). Although the catalytic performance of the electrocatalyst tends to decline, caused by the loss of the highly effective NiOOH species, the initial performance of catalysts can be fully recovered after alkaline retreatment. Most importantly, even after several catalytic cycles, the electrocatalytic performance remains intact as long as the portion of NiOOH species on the catalyst surface is conserved. Moreover, the design of heterogeneous catalysts has been studied in the frame of endogenous asymmetric synthesis and electroanalytical applications. For the enantioselective synthesis, a mesoporous chiral Pt-Ir shell coated on the core of reactive metals, including Fe-Ni alloy and Ni foam, was used as a redox catalyst for the asymmetric synthesis of chiral compounds. The catalytic action relies on the internal driving force based on the oxidation of the reactive metal core. Consequently, the effect of the reactive metal on the enantiocatalytic activity has been investigated. An additional benefit of the porous metal chiral films has also been further illustrated in an unconventional sensing application. Herein, two mesoporous chiral Pt-Ir plates are assembled in a parallel configuration separated by a micro gap. The concept behind this analytical chiral device is to amplify the faradaic current density of the chiral analytes via a redox cycling (RC) process. The multiple sequential redox reactions of a specific enantiomer, corresponding to the chiral structure encoded in the mesoporous Pt-Ir matrices, can occur in the microchannel of the device to selectively enhance the faradaic current of a specific enantiomer.