Development of Bifunctional Metal/zeolite Catalysts for The Catalytic Valorization of Lignin-derived Molecules

**Development of Bifunctional Metal/Zeolite Catalysts for the Catalytic Valorization of Lignin-Derived Molecules**:

- Réf **ABG-131055**
- Sujet de Thèse
- 15/04/2025
- Contrat doctoral
- Institut de Chimie des Milieux et Matériaux de Poitiers
- Lieu de travail- Poitiers - Nouvelle Aquitaine - France
- Intitulé du sujet- Development of Bifunctional Metal/Zeolite Catalysts for the Catalytic Valorization of Lignin-Derived Molecules
- Champs scientifiques- Chimie
- Mots clés- Heterogeneous catalysis, zeolites, biomass

**Description du sujet**:
The transformation of lignin fraction of lignocellulosic biomass into compounds compatible with Sustainable Aviation Fuels (SAF) is a topic of significant interest. Producing SAF from lignin-derived pyrolysis oils represents a major challenge that can potentially be addressed through the development of innovative catalysts. This PhD project aims to design novel bifunctional catalysts combining metals and zeolites to enhance the production of SAF-compatible molecules from lignin-derived model compounds.

One of the key challenges in converting lignocellulosic biomass into renewable fuels is achieving the selective production of hydrocarbons suitable for use as liquid transportation fuels, either for blending or direct consumption. While production of C5-C9 hydrocarbons have proven effective from the transformation of the different family of compounds derived from biomass (phenols, aldehydes, furans), there is significant potential in exploring the selective production of heavier hydrocarbons (C12-C18), particularly suited for high-density fuels such as diesel and jet-fuels. Lignin, the most abundant source of aromatic compounds in nature corresponding to up 30% of biomass composition, is a particularly promising feedstock for the synthesis of bio-fuels. However, the compounds generated from lignin depolymerization through pyrolysis process, such as phenols and guaiacols, typically contain only a single aromatic ring, necessitating C-C coupling reactions followed by oxygen removal to produce hydrocarbons that meet the density and performance requirements for high-energy fuels.

An elegant strategy to achieve selective hydrocarbon production from lignin-derived phenolics involves the combination of hydroalkylation and deoxygenation reactions, using dual-functional catalysts. In this approach, the catalyst plays a central role, typically incorporating a metal component for hydrogenation and a Brønsted acid component for dehydration and alkylation reactions. A particularly promising system combines metal catalysts that selectively hydrogenate phenolic compounds with zeolites featuring strong Brønsted acid sites.

This PhD project aims to study a tandem hydroalkylation/deoxygenation process to achieve efficient one-pot synthesis of high-density fuels from lignin-derived phenolics over rationally designed bifunctional metal/zeolite catalysts. Following goals are defined:

- Synthesis of bifunctional Ni/Zeolite catalysts. Particular interest will be devoted to the impact of the porosity of the zeolite phase (topology of micropores and presence of secondary porosity), confinement of metal clusters in porosity with control of particles size and distribution, and tuning of the metal/Brønsted acid sites balance;
- Study on the impact of intimacy between metal/acid sites and its impact on hydrogenation, dehydration and alkylation reactions;
- Optimization of the balance between dehydration and alkylation reactions (Lewis vs. Brønsted acid sites).
- Impact of the shape-selective properties of zeolites.

**Prise de fonction**:

- 01/10/2025

**Nature du financement**:

- Contrat doctoral

**Précisions sur le financement**:
**Présentation établissement et labo d'accueil**:

- Institut de Chimie des Milieux et Matériaux de Poitiers

The Institute of Chemistry of Environments and Materials of Poitiers (IC2MP) is a multidisciplinary Joint Research Unit (UMR) affiliated with the University of Poitiers and the CNRS (Chemistry and Earth & Universe Sciences). Specializing in chemistry and surface geosciences (UMR 7285), IC2MP was established in 2012 through the merger of four historically significant UMRs in Poitiers (LACCO, LCME, SRSN, and HYDRASA), with a legacy spanning over 40 years. The institute comprises approximately 260 members, including around 100 researchers and faculty, 50 permanent technical staff, and roughly 110 non-permanent members, among whom 90 are doctoral students.- 18/05/2025