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CO2? Capture it and turn it into methane!

The recent scholarly literature tends to show that Combined CO2 Capture and Methanation (CCCM) processes could emerge as one of the practical solutions in the context of CO2 emissions mitigation. Such strategies based on the combined CO2 capture on solid adsorbents and CO2 methanation on metal-based catalysts are both pertinent and practically achievable. This strategy could become relevant for effluents with high CO2 concentrations, operated under moderate flow rates, and where the production of “green” H2 is available on-site.

As we cover in our recent short review paper, both fields of CO2 adsorption and CO2 catalytic upgrading have seen enormous progress over the last decades; high-performance materials are now available both for capture and for methanation. Designing combined processes with distinct units for capture and for methanation is a first option that will mostly require process optimization. It allows to treat complex gas effluents on the one hand and to perform the methanation under “clean” conditions on the second hand. Processes where the two types of solids (adsorbent and catalyst) are combined in the same adsorption/methanation unit constitute a second option. In these cases, the catalyst not only has to exhibit high performance in its normal operating conditions (during methanation), but also has to withstand the operating conditions that are applied during the capture step (and vice versa concerning the adsorbent). Finally, a third strategy which is being intensely investigated is the use of dual functional materials (DFM), bearing both a capture function and a reduction function. The associated processes benefit from the proximity between the adsorption sites and the reduction sites, between which CO2 spillover can occur. Yet again, the development of efficient formulations is conditioned to the stability of both types of sites in the full cycle of capture and methanation.

Valentin Smeets (PhD thesis): “New synthetic approaches to efficient Ti-SiO2 epoxidation catalysts”

Welcome to all for the PhD defense of Valentin Smeets! It will take place at UCLouvain on October 24 (see info on the announcement below and here).

Abstract

The epoxidation of olefins is a subject of considerable fundamental and industrial interest as epoxides are involved in the manufacture of a wide range of valuable commercial compounds. This reaction is typically catalyzed by heterogeneous Ti–SiO2 titanosilicates, which were first introduced in the 1970s. Among these catalysts, TS-1 zeolite is industrially used for the production of propylene oxide. Nevertheless, despite its attractive performance, this catalyst is mainly restrained to lower substrates, as bulky molecules cannot access the micropores of the zeolite. Intensive efforts were therefore made in the past decades to develop new titanosilicate catalysts, either amorphous or crystalline, so as to improve the catalytic performance as well as to expand the reaction scope. This thesis tackles challenges that are omnipresent in the current research on solid titanosilicate catalysts.

On the one hand, the intricate relation between the physico-chemical properties and the catalytic performance is highlighted. New titanosilicates prepared by atypical sol-gel techniques (non-hydrolytic sol-gel, aerosol-assisted sol-gel, direct emulsion templating, dry gel conversion) are investigated, with a particular focus on selected physico-chemical properties, namely the surface functionality, the texture and pore architecture, and the macroscopic morphology. Each catalyst is characterized in details and its catalytic performance is evaluated under specific reaction conditions and compared to the benchmark TS-1 catalyst.

Even though hydrogen peroxide is an attractive oxidant for the green epoxidation of olefins, its current industrial production raises some questions. Therefore, on the second hand, the chemo-enzymatic production of epoxides with in situ enzymatic production of H2O2 is investigated. Exploiting the spray-drying technique, TS-1 crystals are assembled into hollow microstructures that can accommodate large amounts of enzymes on a single solid. Upon optimization of the operating conditions, this controlled design is shown to be effective for chemo-enzymatic epoxidation and also appears as a promising way to develop new multifunctional materials.

Jury members :

  • Prof. Damien Debecker (UCLouvain), supervisor
  • Prof. Eric Gaigneaux (UCLouvain), supervisor
  • Prof. Yann Garcia (UCLouvain), chairperson
  • Prof. Michel Devillers (UCLouvain), secretary
  • Prof. Carmela Aprile (UNamur, Belgium)
  • Prof. Michiel Dusselier (KU Leuven, Belgium)
  • Dr. Cédric Boissière (Sorbonne Université, France)

Cédric Boissière to give a seminar on “Silica-based nanotherapeutic vectors” at UCLouvain – Sept 10

It is my pleasure to announce that Dr. Cédric Boissière, a prolific inventor and outstanding chemist from Sorbonne Université, will give a seminar at our institute. Cédric is very active in materials chemistry, in particuler in sol-gel science and processing, focusing on porous materials, thin films, heterogeneous catalysts, sensors, nanovectors, etc.

Nano-vectors are fairly recent nanomaterials aiming at helping diagnosis and treatment of heavy diseases such as cancer. The huge research effort produced in the last fifteen years achieved an impressive number of different organic or hybrid organic/inorganic nanomaterials integrating one or several functionalities ranging from contrasting agent (helping at imaging diagnosis) or therapy (drug release, hyperthermia, radio-sensitising agent, etc.). Yet, so far, commercialized nanovectors are fairly simple and mostly organic-based nanomaterials. The reason of this discrepancy comes from the fact that multifunctional platforms (either organic or hybrid) require expensive and delicate synthesis pathways, and/or use complex chemical compositions, and/or makes difficult their dissolution and excretion control.

In this presentation will be shown past and recent synthesis strategies of silica-based nanovectors developed at LCMCP (Sorbonne Université). The adequate coupling of soft-chemistry and processing allows developing in very simple ways multifunctional platforms with a constrained number of constituents that offer a very good functionality/synthesis complexity compromise. A dissolution kinetic study will be presented. It will show that their use is realistic from pharmaceutical development point of view.

Useful references:

Conférence en vidéo: Préparation de catalyseurs hétérogènes à porosité contrôlée par le procédé aérosol

Le 22 février dernier, à l’invitation de Clément Sanchez, j’ai donné une conférence au Collège de France. Mon intervention s’inscrivait dans le cadre d’un colloque sur les matériaux poreux. Une belle occasion de partager ce que nous développons dans ce domaine, pour la préparation de catalyseurs hétérogènes, avec un focus sur le procédé aérosol.

Damien Debecker (UCLouvain), 22 février 2019, Collège de France, colloque “Synthèse, Propriétés, Applications des Matériaux Poreux : des nanopores aux macropores” organisé par le professeur Clément Sanchez (Collège de France). Plus d’informations: www.college-de-france.fr

Les procédés aérosol sont connus et implémentés depuis plusieurs décennies pour l’obtention de matériaux divisés aux propriétés variées. Les caractéristiques techniques des procédés aérosol rendent ces méthodes attractives pour la production de matériaux et nanomatériaux en mode continu, à large échelle et à façon. La versatilité de ce mode de production est spécialement intéressante dans le domaine de la catalyse hétérogène, où le contrôle fin des propriétés texturales, structurales et chimiques est essentiel. Nous l’avons utilisé pour préparer des catalyseurs aux propriétés basiques exacerbées, intéressants en chimie verte pour la synthèse du carbonate de glycérol. Nous l’avons également implémenté pour la préparation de catalyseurs structuré pour l’abattement des suies dans les échappement des moteurs diesel.

Les caractéristiques techniques des procédés aérosol permettent la production de catalyseurs hétérogènes performants, en mode continu, à grande échelle. Voir notre revue de la littérature dans Chem. Soc. Rev. 2018.

En particulier, la méthode “aerosol-assisted sol-gel” (AASG) a permis le développement de formulations catalytiques à hautes performances dans une série d’applications. La méthode est basée sur la chimie sol-gel classique, mais réalisée en un temps très court, durant le séchage des gouttelettes d’aérosol, souvent en présence d’agents texturants sacrificiels. Elle aboutit à la formation de particules microniques ou submicroniques, inorganiques ou hybrides, avec un excellent contrôle à la fois sur l’homogénéité et sur la texture (porosité calibrée, potentiellement multi-échelle, et adaptable). Dans la vidéo je passe en revue une série d’exemples de systèmes catalytiques obtenus par le procédés sol-gel couplé à l’aérosol, qui ont montré des performances intéressantes dans diverses réactions d’intérêt : métathèse des oléfines, méthanation du CO2, synthèse du lactate d’éthyle, époxydation des oléfines. J’expose aussi la conception de catalyseurs bi-fonctionnels combinant à la fois la fonction catalytique inorganique d’une zéolite microporeuse et la fonction biologique d’une enzyme.

Catalyseur Ti–SiO2 à porosité hiérarchisée, avec une grande dispersion du Ti et une haute activité pour l’époxydation des oléfines. Voir Chem. Mater. 2019.

Weiyi Ouyang joins our group as a postdoctoral fellow


The group was recently reinforced with the arrival of Weiyi Ouyang, who will bring his expertise in the catalytic upgrading of biomass and in MOF synthesis.

Weiyi did his PhD with Prof. Rafael Luque as a supervisor (NANOVAL, University of Cordoba, Spain) while he was also a Marie Curie early stage researcher in the Photo4Future project.

Weiyi is very experienced in preparing and characterizing various nanomaterials, such as metal oxide nanocomposites, porous aluminosilicate (SBA-15), metal organic frameworks, etc. Moreover, he is also good at investigating their catalytic performance in valorization of biomass derived platform molecules. He is currently hired on the ARC project aiming at investigating the effect of hydrophilicity and hydrophobicity of the catalysts on their catalytic performance.

Follow him on Twitter! (@OuyangWeiyi)

6th International Conference on Multifunctional, Hybrid and Nanomaterials: presenting our results on the stability of hydrophobic metallosilicates

Ales Styskalik is at the “HYMA Conference” in Sitges (Spain) to present an oral communication: «Ethanol dehydration over hydrophobic aluminum and niobium silicates: Influence of homogeneity of metal mixing on catalytic activity and stability of Si−C bonds». Here is his story, in brief.

Ethylene is widely used in chemical industry, mainly in polymer production. Nowadays it is being produced by petrochemical industry. (Bio)ethanol dehydration to (bio)ethylene is an interesting process that can become a competitive alternative to oil based production of ethylene, however catalysts for this reaction suffer from low activity and hydrothermal stability. Our intention was to improve their performance by increase of hydrophobicity. For this reason organic groups were introduced into the metallosilicate catalysts. To prepare these hybrids, we exploit the power of non-hydrolytic sol-gel chemistry.

From the very beginning we were facing serious issues with hydrothermal stability especially for materials containig aromatic groups connected via a direct Si−Caromatic bond. That was surprising because hybrid silica materials were proved to feature high stability against hydrolysis: while hydrolysis in hydrophobic silica occured at 400 °C, we have observed an extensive damage to metallosilicates already at 200 °C. We have shown that the instability is brought by introduction of partial charges to silica network due to differences in electronegativity between Si and the metal atoms incorporated. The more homogeneously were metals and thus partial charges distributed within the network, the lower was the catalyst stability. This stability issue was solved by incorporation of organic groups using precursors with stable Si−Caliphatic bonds (Figure). These are hydrothermally stable up to 350 °C. Aromatic groups can be maintained when using xylylene bridges.

Simply Complex: Precisely Manufactured Simple Molecules for Today’s Applications

On November 30, Dr. Rob Hart, head of R&D from The Shepherd Chemical Company (Cincinnati, USA) is invited to present a seminar at our Institute.

“It turns out that you can teach an old dog new tricks”.

Rob Hart, 2018

You are all invited to attend and discover how the chemistry and manufacture of simple molecules like basic copper nitrate, cobalt neodecanoate, zinc octoate and chromium acetate is in fact complex and interesting. Advanced characterization techniques, precise chemical engineering and strategic partnerships create opportunities for these types of materials to play a prominent role in technologies that impact us every day. 

Rob Hart is the Head of R&D from The Shepherd Chemical Company . He obtained his bachelor’s degree from University of Wisconsin and his Ph.D.from Indiana University where he worked with Prof. Josef Zwanziger on ceramic glasses. After graduation, he did a post-doc at Argonne National Lab where he worked with Chris Benmore, Ph.D. on characterizing optics, glasses, refractories, molecular liquids, etc. with neutron and x-rays cattering. Rob joined Shepherd Chemical in 2005 and has served numerous roles in the company from chemist and characterization lab manager to production manager and now Head of R&D.

Looking forward to meeting you all there!

Damien


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