Synergistic metal oxide / oxo-hydroxide electrocatalysts for converting lignin-to-value-added products

• Applicant: Dr. Dandan Gao
• Subject Area: Solid State and Surface Chemistry, Material Synthesis
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 510966757

As one of the globally abundant biomasses, lignin is an ideal and important feedstock for the sustainable production of fuels, bulk and fine chemicals, particularly aromatic compounds. However, due to its structural complexity and chemical properties, selective lignin conversion is challenging and often requires harsh conditions involving elevated temperature and pressure. In this project, the applicant proposes the development of a modern electrochemical oxidation method based on robust non-noble metal electrocatalysts integrated in a flow electrochemical reactor. This is expected to lead a green and scalable lignin conversion approach under mild conditions with high selectivity, efficiency and yield. The project combines concepts from catalyst/electrode design and fabrication to materials-in-reactor integration, and in-depth understanding of the conversion mechanism using physicochemical in situ analytical methods. In addition, this project will merge the applicant’s expertise in physical electrocatalytic mechanistic studies and catalyst development with the expertise of the host group in organic electrosynthesis. Specifically, the applicant will immobilize mixed bimetallic metal oxides or oxo-hydroxides onto 3D porous metal foams via facile wet-chemical, electrochemical or hydrothermal deposition methods. This will result in stable mechanical and electrical linkage between catalyst and electrode support. Variation of the composition and nanostructures of the catalysts will allow investigation of the bimetallic synergism, which will also facilitate control/optimization of electrochemical performance in terms of reactivity, durability and selectivity. Electrode integration into custom-made flow electrolyzer and separation setups will enable enhanced control over conversion and avoid product overoxidation under continuous operation. The system will be assessed by in situ/operando electrochemical studies to provide insights into electrode performance under electrocatalytic conditions. In sum, this project will open a new avenue for efficient and selective lignin conversion via an original electrochemical oxidation technique, involving advanced catalyst/electrode design, scalable flow electrolyzer integration and physicochemical mechanistic investigation by in situ/operando methods.

• DFG Programme: WBP Position