The Department of Functional Materials and Catalysis would like to announce the 3rd mini-symposium, which is part of “270065-1 SE Seminar für Chemie und Technologie der Materialien (2024S)”.
Invited Speakers:
Prof. Marco Faustini, Sorbonne Université, Collège de France, CNRS, Paris, France
Title : Exploring the chemical space and the structural diversity of colloidal based porous materials
Functional porous materials play a pivotal role in several energy and environmental related applications. The performance of these materials largely depends on our ability to shape them at various scales, control their composition and "program" their response. During this presentation, I will discuss our recent endeavors in designing porous materials by colloidal self-assembly by following on three directions:
(i) Exploring the chemical space: I will show that the reactivity of polymeric colloids can be engineer to fabricate porous materials with "complex" compositions such as noble metal oxides,1 metals,2 High Entropy Alloys3 for (electro) catalysis4 and lithography.5
(ii) Engineering defects: a drawback, crack formation in colloidal assembly, can be harnessed towards an original patterning method for porous oxides6 or Metal-Organic Frameworks (MOFs)7 for photonics.8
(iii) Programming in time: I’ll illustrate our recent efforts in designing self-regulating porous materials;9 taking inspiration from living systems, feedback mechanisms can be integrated in porous materials such as colloidal MOFs10 to program actions in time.
1. M. Elmaalouf; M. Odziomek; et al, Nature Communications, 12, 3935, 2021.
2. M. Gayrard et al, , Small, 18, 2104204, 2022.
3. M. L. De Marco; et al, ACS Nano, 16, 15837-15849, 2022.
4. M. Faustini; et al, Advanced Energy Materials, 9, 4, 1802136, 2019
5. M. Gayrard; et al, Nano Letters, 21, 5, 2310-2317, 2021.
6. M. Odziomek; et al , Advanced Materials, 34, 2204489, 2022.
7. O. Dalstein; et al, Angewandte Chemie International Edition, 56, 14011-14015, 2017
8. F. Thorimbert; et al Nature Communications, 2024
9. M.L. De Marco; et al, Chemistry of Materials, 2023
10. C. Avci; et al, Advanced Materials, 2104450 2021.
Dr. Emma M. Björk, Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
Title: Designing mesoporous materials for a sustainable society
Materials science plays a crucial role in meeting many of the UN’s sustainable development goals, and mesoporous materials, characterized by a large specific surface area (>500 m2/g) and pores in the range of 2 – 50 nm, are anticipated to play a critical role to reach them. For example, development of noble-metal-free catalysts for water splitting and recombination enables storage of sustainable energy from wind- and solar power, and carriers of antimicrobial peptides and therapeutic ions are needed to reduce the usage of antibiotics. The materials are synthesized using soft-templating with micelles in sol-gel or hydrothermal syntheses which enable controlled characteristics for the different applications. In this talk, I will focus on how understanding and controlling the material formation processes enable optimization of material characteristics.
Mesoporous silica film can be used as drug delivery systems from implants, catalysts, and sensors. By combining in situ IR-spectroscopy with small angle x-ray scattering, insights to both the formation of the silica network and the micelle evolution are obtained. By adding hydrophobized substrates to the synthesis solution when the micelles are slightly silicated, it is possible to grow films with an available surface area per substrate area is up to 170 m2/m2. By careful tailoring of the substrate functionalization, it is possible to grow homogeneous films on silicon wafers, titanium screws, and glass beads. The films are biocompatible and can be used to deliver both hydrophilic and hydrophobic drugs from e.g. an implant surface.
Mesoporous transition metal oxides are sustainable alternatives to the Ir-, and Ru-based electrocatalysts that today are used for water splitting and recombination in electrolyzers and fuel cells. By tailoring the roughness of nanoporous NiO, the oxygen evolution reaction requires less over-potential compared to commercially available Ir/C-catalysts. By altering the composition, the product selectivity in the oxygen reduction reaction can be tuned. This enables noble-metal-free local production of O2, H2O2, and OH-.
Prof. Feng Ryan Wang, Department of Chemical Engineering, University College London, UK
Title: Catalysis enabled by operando spectroscopy: from fundamental understanding to innovative materials
Heterogeneous catalysis is of prominent importance for modern society. For example, the Fe catalysed NH3 synthesis process provides nitrogen fertilizers that lead to food production for at least half of the world’s population. It is even more important in the circular economy, providing process solutions for future energy conversion, fuel production, and waste recycling. Yet the understanding of reaction mechanisms is still limited due to the complexity of surface catalytic systems and the lack of characterization methods to directly observe surface process under working conditions.
In this talk, I will introduce new experimental designs to utilize synchrotron X-rays and X-ray free electron laser-based operando spectroscopy to identify active centres and rate determine steps, which leads to the development and synthesis of novel materials that have significantly improved catalytic performance. I will present recent method development in my group:
1. Measuring the half reaction rate to determine rate limiting steps in catalysis.
2. Measuring bond energy upon the formation of oxygen vacancies.
3. Measuring dynamics of elementary electron transfer from support to metal active site at fs to ps time scale, help to shoot the molecular movie of a single catalytic process.
With these first-time observations, we have been able to develop new catalysts with 5-100 times better performances than those in existing reports for emission control, H2 production, and fuel cell applications. Our new operando X-ray methods have been used beyond catalysis to energy storage and conversion systems. Such innovation has great potential in wide engineering applications.