Description of the thesis topic

Context of the Study
One of the main challenges facing the humanity is to decrease the use of fossil resources for energy and chemistry toward more sustainable routes. If for energy numerous solutions are being explored as for example, hydroelectric power plants, sunlight and wind for electricity production; biomass to fuel transformations; hydrogen as alternative fuel, etc...; for chemicals current researches tend mainly to explore ways of developing alternative bio-sourced materials to replace mainly polymers and solvents, but leaving current “fine chemicals” based on petrochemical resource that are depleting. This situation is clearly handicapping when addressing the pharmaceuticals since more than 80% of the active molecules used in this industry are based on aromatics.
As a partial answer, this project focuses on the valorization of lignin-rich co-products from food or paper industries for producing aromatic building blocks. Our proposal aims at developing the chemical valorisation of lignin rich resources, coming from breweries and paper mill industries, for the synthesis of small aromatic molecules usable in the fine chemical industries. To reach such an objective, heterogeneous catalysts will be engaged in a catalytic pathway for conducting lignin transformation to C9-aromatic units.
To summarize, the project aims at providing new routes for upgrading lignin contained in co-product from breweries and paper mill industries. Environmentally friendly methodologies are planned for performing lignin depolymerization in water. Recycling metal-catalysts is also one of the targets to reach.
The challenge lays in finding efficient and selective heterogeneous catalytic systems able to selectively transform lignin to cinnamic derivatives in high selectivity and good yields, preferably under environmentally friendly conditions.

Activity and Methodology
Lignin upgrading through selective depolymerisation (i.e. pyrolysis; oxidative, acid/base or enzymatic depolymerization…) is the subject of several research. Most of these procedures often led to low yield in added-value products, generally as C6-aromatic monomers. A recent report shows that transition metals doped aluminum phosphates were able to convert selectively lignin to C9-cinnamic derivatives under hydrogen. The selectivity depends strongly on the catalyst formulation and due to high reaction temperature yields stay low. We believe that through catalyst design higher control of the acid/base properties and hydrogenation capacity of the catalysts could help to reach a process for converting selectively lignin toward cinnamic derivatives under mild conditions (typically 25-100°C, 2-20 bar of hydrogen).
To answer the challenge of the project, the development of non-noble metal supported catalysts will be engaged. Initially, Ni-based catalysts will be evaluated. Phosphate materials will be used as support, starting with nickel derivatives. It is also planned to prepare bimetallic system in which a very low noble metal charge will be used. Characterization techniques include Elemental analysis, TEM, MEB, BET, DRX, Calorimetry… All techniques are available at IRCELYON or IFPEN that is a strong partner of the study.
Once fully characterized, the catalysts will be applied to lignin depolymerisation in batch and three-phase flow reactors (all available at IRCELYON) under aqueous media under reductive atmosphere. Focus will be made on the selectivity of the reaction toward C9-units. Optimization of the reaction conditions will be performed.
The detrimental effect of some impurities will be investigated to improve the activity, life-time and space-time yield of catalysts/reactors. The reaction mixtures will be analyzed through several complementary techniques including, for example, GC/GCMS, LC/LCMS, Aqueous phase SEC, NMR, FTIR..., eventually after fractionation following previous reports. Kinetic studies will be realized, as a tool for optimizing the reaction. This implies to follow closely the composition of the reaction mixture versus the time to draw the evolution of the reagent conversion, and that of the product yields, versus the time. Kinetic models will be developed and simulated to reach kinetic constants.

Work Context

IRCELYON is a joint research unit between the CNRS and the University of Lyon, which brings together the heterogeneous catalysis expertise of the Lyon region to create the largest catalysis laboratory in France and Europe. The laboratory comprises 80 permanent researchers from the CNRS and the University of Lyon, as well as a similar number of doctoral and postdoctoral students.

The scope of the position includes:
• A stimulating working environment with close contact with research staff
• An on-site restaurant offering affordable lunch options
• Partial reimbursement of transport tickets (75%) or a sustainable mobility package
• A site accessible by public transport + secure car/bicycle parking
• A consortium of highly qualified scientists willing to provide the doctoral student with all the necessary assistance to carry out the proposed study.

The position is located in a sector covered by the Protection of Scientific and Technical Potential (PPST) and therefore requires, in accordance with regulations, that your arrival be authorized by the competent MESR authority.

The position is located in a sector under the protection of scientific and technical potential (PPST), and therefore requires, in accordance with the regulations, that your arrival is authorized by the competent authority of the MESR.

Constraints and risks

Skills
The candidate should have an interest in the preparation of supported-metal heterogeneous catalysts associated to knowledge of their characterization techniques (XRD, TEM, texture determination). Knowledge of common analytical techniques associated to characterization of the reaction mixtures (GC, HPLC…) is primordial. While not mandatory, working with autoclave and knowledge of kinetic studies will be appreciated.

General Information
Modalities of application: To apply, please address a motivation letter together with a Curriculum Vita to the contact. References from previous working position will be helpful. Join the last two years academic achievements (note transcripts, diploma…).
Type of Contract: PEPR project BioMCat, CDD

Constraints and risks
This work is a part of the larger PEPR project BioMCat, developed in close collaboration with BBF (INRAe Marseille), IPHC (UNISTRA), IFPEN (Research center of Lyon) and a subcontractor (FCBA).
Regular meetings with the partners are expected, at least every 3 months.
Regular research reports (twice a year) should be delivered by PhD student candidate.