Sol-gel routes to nanostructured bifunctional catalysts for the direct conversion of (bio)ethanol to 1,3-butadiene
(2023)
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- Authors
- Supervisors
- Debecker, Damien
- Abstract
- Heterogeneous catalysis can become the pivotal point to shift from petro-based to renewable bio-based resources as feedstocks for those chemical processes. 1,3-butadiene, a key monomer in the tyre industry, attracts a lot of research attention due to a fore coming market instability. In parallel, the production of bioethanol is expected to reach 150 billion litres in 2032. Thus, the catalytic conversion of ethanol to 1,3-butadiene is under extensive research. To maximize the industrial viability, the synthesis of these catalysts must be straight-forward and should consist of as few steps as possible. Furthermore, the ethanol-to-butadiene reaction requires bifunctional catalysts with highly dispersed Lewis acid sites and metal nanoparticles as redox sites. These challenges are discussed in this thesis and addressed via the use of innovative sol-gel techniques. In the first half of this thesis, an aerosol-assisted sol-gel approach is used to synthesize Ag-Ta and Cu-Ta-based catalysts with advantageous mesoporous texture preventing mass transfer limitations, inserted Ta atoms inside the silica matrix serving as Lewis acid sites and well dispersed small Ag or Cu nanoparticles as redox sites. Understanding the catalyst properties and tuning them allow us to obtain remarkable catalytic performance. In the second half, the non-hydrolytic sol-gel approach is leveraged for the synthesis of Cu-Ta-based catalysts. First, two different synthesis routes, the ether route and the acetamide elimination route, are compared to better understand the active sites speciation, their proximity and the influence of those characteristics on catalytic properties. The acetamide elimination route is deemed more appropriate for the ethanol-to-butadiene reaction. The mixing of both routes in a so-called “delayed addition” of a fraction of precursors yield bifunctional materials with properties originating from both distinct synthesis routes and reasonable catalytic performance.
- Affiliations
Citations
Dochain, D. (2023). Sol-gel routes to nanostructured bifunctional catalysts for the direct conversion of (bio)ethanol to 1,3-butadiene. https://hdl.handle.net/2078.5/236265