Anaerobic digestion (AD) is a microbiological process of degradation of the organic matter which produces biogas rich in methane that can be converted into valuable electrical and thermal energy. It is commonly used to manage different types of organic waste at industrial scale using anaerobic digesters. However, this bioprocess is not fully mastered and still has an important potential for improvement. One of the major limitations of AD is the important susceptibility of the microbial communities to changes in operational conditions of the digesters. It can lead to unstable methane formation. Controlling AD microbial community stability, though, is not a trivial task. Knowledge on the determinants of anaerobic microbial process stability (i.e. the conditions and the succession of microbial events that allow maintaining a balance after a disruption or, on the contrary, that generate a domino effect leading to total failure) over time is still missing. Emerging omics high-throughput approaches can now lead to unprecedented data to portray AD microbiome. Metagenomics, metatranscriptomics, metaproteomics and metabolomics enable to describe a community at different levels (genes, gene expression, and metabolites production). Appropriate and efficient analytical methods are required to analyse these big and complex data and unravel the intricate networks of functional processes of AD. Novel computational and statistical methods are progressively becoming available to fully harvest and integrate these complex datasets. In this context, the aim of STABILICS is to conduct the first sets of high-throughput multi-omics longitudinal experiments, with an unprecedented sampling depth, in anaerobic digesters under constant environmental parameters or subject to different model perturbations created by the addition of NaCl. Experiments in lab-scale semi-continuous reactors will be set-up and monitored in the long run (more than one year). Two levels of analysis will be applied. 1) A high frequency monitoring of different descriptors of microbiota activity, where non-targeted metabolomics and isotopic analyses will characterise the degradation pathways and metabarcoding of RNA and DNA will target both active and present microorganisms. 2) An in-depth monitoring of microbiota functioning with both metagenomics and metatranscriptomics on selected samples and conditions. These unprecedented sets of data will be thoroughly analysed and integrated using cutting-edge statistical methods. For example, multivariate dimension reduction methods will be used for data mining, omics integration and feature selection; specific analytical framework for longitudinal data will be developed. The objectives of this interdisciplinary project will be 1) to evaluate at different omics levels the dynamics of AD microbiome in long term and replicated time course experiments, 2) to describe the succession of events that, under stress, leads to microbiota equilibrium unbalance and digester disruption or on the contrary microbiota equilibrium preservation and maintenance of stability, 3) to propose an original analytical framework of multi-omics longitudinal studies accounting for temporality, and 4) to deliver generic knowledge to understand the determinants of perturbations.

Anion Exchange Membrane Water Electrolysis (AEMWE) is a very promising technology for producing clean H2 at a target cost of 2 $/kg. Like Proton Exchange Membrane Water Electrolysis (PEMWE), this membrane-based technology has the advantages of an “all solid” system (coupling with intermittent energy sources, high energy efficiency, high purity of H2). In addition it allows the use of earth abundant transition metals as electrocatalysts for both the evolution of O2 at the anode (OER) and of H2 at the cathode (HER), as opposed to PEMWE, where these catalysts rely exclusively on rare and expensive Platinum-Group Metals (PGM). However several challenges remain for AEMWE to reach as high and stable performance as PEMWE and be spread on the market. To achieve the increase of performance in AEMWE, essential components of the MEA must be optimized, with a specific emphasis on HER catalysts. Indeed, while being very fast in acidic conditions, the HER kinetics in alkaline medium are slow because they imply the adsorption of a water molecule, generally considered as the rate-determining step. In order to improve the rate of this first step, the new concept of heterofunctional catalysts has recently emerged. It consists in the tight interfacing of two or more active components so as to create a synergy between them, thus favoring water dissociation. In particular, bifunctional catalysts combining (i) one material with good water dissociation properties and (ii) another one with appropriate hydrogen adsorption energies, have displayed a 7-fold increase in alkaline HER rate. In the HYKALIN project we propose to significantly improve the performances of AEMWE so they can compete favorably with PEMWE. To do so, we intend to cover some untouched aspects in this field, through an integrative approach dealing with both fundamental and more applied aspects. In particular, we aim at: 1) Developing a new class of transition-metal-based heterofunctional catalysts being highly active for the HER in alkaline medium. Ni, Co, Cu and Mo are selected because they are already known to be very active for this reaction. We target composite catalysts associating a metal with either an oxide or a sulfide. They will be obtained by a 2-step process to achieve a maximum number of interfaces and catalytic sites. In the first step, we will synthesize MM’ alloys where the two metals are distributed at the nanoscale, using either polyol or spray-drying processes. In a second step, these alloys will be converted in M@M’Ox and M@M’Sx by thermal treatment or solution route. We will focus on producing specific porous morphologies which are crucial to induce good gas and water transport inside the MEA in order to improve the performances. 2) Deeply characterizing their electrochemical properties as well as their structure by operando X-ray spectroscopy to understand and improve their activity. Chemical nature, stoichiometry and morphology of the catalysts will be investigated in order to understand the behavior of the materials in the catalytic layer under functioning conditions. Ab initio and DFT calculations will also be crucial in this section to complement the interpretation of the experimental results. This should allow us to propose a comprehensive mechanism for alkaline HER. 3) Finally the best catalysts will be processed into membrane electrode assemblies and tested in situ in AEMWE. We will optimize MEA preparation and investigate the best operation conditions for the 5 cm2 electrolysis cell in order to achieve performances better than Pt/C. In a second step, we will perform degradation studies and get information on the mechanism of performance decrease. This fundamental and applied approach will significantly improve knowledge in the still emerging field of alkaline electrolyzers and should allow, in the mid-term, major breakthroughs in the domain of advanced water electrolysis and carbon-free hydrogen production.

In this proposal, we are discussing the opportunity of studying the electron transfer reactivity of divalent organolanthanides complexes. This type of complexes has known a growing attention in the last few years and few groups around the world contributed to the description of intriguing reactivity as well as singularities in electronic structures. The latter have been challenged by spectroscopic observations that are not in agreement with the traditional believe of pure electrostatic bonds but are also far from a classical covalent model. A better understanding of the overall bonding picture may be overcome by making new divalent lanthanides with simple ligands, typical of organometallic chemistry, such as the indenyl ligand or amides based ligands, and divalent lanthanides precursors. We will be engaged in making new divalent molecules with the classical Sm, Eu and Yb lanthanides but also the more challenging Tm, Dy and Nd. The divalent lanthanides complexes are extremely reactive toward – even weak, oxidants. We will take advantage of having stable divalent complexes to study the single electron transfer from the reactive divalent metal to redox non-innocent ligands such as N-aromatic heterocycles and P-aromatic heterocycles. Characterization of these complexes will be performed with routine experimental techniques of synthetic organometallic chemists (such as X-ray diffraction, multi- atomic NMR, absorption visible spectra, IR, electrochemistry and magnetic studies) but we are also interested in this project to have a deeper look at their electronic structure using optical spectroscopy measurments, almost an empty field of research for organolanthanides. As to reinforce the expected experimental observations, a strong feedback from theoretical chemistry is proposed in the enclosed document in order to gather as much details we may and lean toward a decent physical model. If some of the complexes considered in this proposal are expected to be stable to allow their isolation; further reactivity is also expected and examples of C-H activation and of reversible C-C coupling have been observed in our preliminary work. We would like to take advantage of such reactivity to react these molecules with small molecules such as N2, CO2 or N2O. Assisted with theoretical calculations of energy profile and by experimental kinetics, their reactivity will be carefully studied and aim at relating the main outcomes to the electronic structure of the parent molecules.

Nature achieves the selective transformation of simple and inert chemical building blocks into highly functionalised molecules. The amino acid family is one representative example which features a multicarbon backbone and different functional groups. Although the activation of small molecules such as carbon monoxide (CO) and carbon dioxide (CO2) has attracted a lot of recent attention, systems allowing the transformation of these C1 building blocks into multicarbon (C2+) products are scarce, with very little precedence for their functionalisation into value-added C2+ molecules of high general interest. In this JCJC project, I describe an innovative strategy using divalent lanthanide complexes for the activation and reductive coupling of CO into reactive oxocarbon products. Upon treatment with CO2, very reactive intermediates are formed that allow C–H activation on typically inert hydrocarbon substrates, as well as other functionalisation patterns through the formation of new C–C or C–N bonds. Supported by preliminary results, the goal of this project is to create functionalised molecules of high structural complexity through a unique activation and functionalisation procedure of CO and CO2. Following the functionalisation reactions, I will develop strategies for the recycling of the active divalent lanthanide complexes under mild conditions. For this purpose, electrochemical procedures will be of high interest as they constitute resource-economical alternatives to the use of external reducing agents. The ultimate goal is to achieve electrocatalytic procedures for these transformations. Successful results will open new avenues in the field of small molecule activation, as value-added functionalised C2+ products will be directly formed from simple abundant and polluting gaseous molecules, therefore minimising our dependency on pre-functionalised petroleum-derived reagents.

Continuous processes based on Structured Catalytic Supports (SCS) are widely used in industry. Indeed this type of support allows an important surface over volume ratio, a small pressure loss, efficient mass transfers, an intimate mixing of the reagents, and an easy separation of the products from the catalyst. Among the variety of SCS, open cell foams are prime candidates, which fulfill all these features. Of ceramic or metallic constitution, these host architectures are ideal supports for metallic particles. The preparation of these foams however requires several steps, and the physisorption of metallic particles a thermic treatment at very high temperature. This expensive and energy consuming way of preparation represents an important drawback in the development of this kind of catalyst, especially when taking into account the current economic and ecological constraints. Moreover these foams present a number of others drawbacks inherent to their structure: (i) they are heavy and thus difficult to handle, (ii) they are not flexible and usually display micro-cracks, which render them breakable, (iii) they present many closed cells, which renders the reproducibility unpredictable, and (iv) the recovery of the expensive catalyst adsorbed on the foam often necessitates numerous chemical treatments in highly corrosive media. With POLYCATPUF, we propose an alternative based on the use of polyurethane open cell foams (OCPUF). These foams, commercially available in very large quantities and at low cost, present the same structural properties than ceramic or metallic foams, with the advantage to be easily engineered because of their lightweight and mechanical flexibility (elastomer). Recently, we have demonstrated that the whole surface of this polymeric structured material can be efficiently coated with polydopamine (PDA). This layer of PDA (OCPUF@PDA) allows the grafting of inorganic nanoparticles, as well as the covalent anchoring of organic compounds (Patent WO 2016 012689 A2). Moreover this coating process is industrially valuable because it operates at room temperature in water in the sole presence of dopamine and a buffer. These preliminary results constitute the basis of our project. POLYCATPUF is a frontier research project that involves the close collaboration of three academic partners, mastered in surface science and materials, catalysis, and chemical engineering, and of an industrial partner. A consortium based on an experience of several years between the partners. The project aims to demonstrate all the potentialities offered by open cell polymeric foams as support for both homogeneous and heterogeneous catalysts. First of all, the covalent anchoring of homogeneous catalysts opens the door to a large variety of catalysts that were unconceivable with ceramic or metallic foams. The possibility to graft both single-site and multi-site catalysts allows conceiving processes of combined catalysis. Thanks to the presence of an industrial partner, the use of OCPUF as catalytic support will also be evaluated in an industrial reactor. Finally based on the elastic properties of OCPUF, innovative reactors will be envisioned. The use of these OCPUF as catalytic supports may thus have a significant scientific, technologic, economic, and ecologic impact on the current industrial processes, from which might benefit the whole society.