FOR 5715:  Bridging Concepts in Thermo- and Electro-Hydrogen Peroxide Catalysis (HyPerCat)

• Subject Area: Thermal Engineering/Process Engineering ; Chemistry
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 525028514

Thermo- and electro-catalytic hydrogen peroxide synthesis have attracted growing interest, triggering efforts to gain a combined understanding of the underlying mechanistic concepts. For sustainable hydrogen peroxide production there are three future scenarios: (1) a modified anthraquinone process where hydrogen is supplied from electrolyzers, (2) the direct selective hydrogen peroxide synthesis via small-scale thermal heterogeneous catalysis using electrocatalytically derived hydrogen (t-HP) and (3) the direct selective electro-catalytic reduction of oxygen to hydrogen peroxide (e- HP). From a scientific perspective, it is interesting to compare these processes at the various scales (from the atomic view with a focus on the reaction mechanisms and catalyst active sites to the design of the reactor taking heat and mass transfer limitations into account), but there is also the examination of value chains at the industrial scale. While this seems challenging at first sight, we believe that hydrogen peroxide synthesis is a well-suited test case for our studies as t-HP and e-HP process conditions are quite similar, in terms of (1) the catalytic materials and (2) the reaction conditions. Moreover, the reaction network of hydrogen peroxide synthesis is rather simple and involves only two reactants (hydrogen, oxygen) and two products (hydrogen peroxide, water), but still presents a formidable activity-selectivity challenge. Therefore, the objective of this proposal is to investigate both t-HP and e-HP with the aim to derive an in-depth understanding of the factors governing activity and selectivity across the scales (from catalyst surface to reactor) with the specific focus to unravel similarities and differences between the thermo- and electrocatalytic routes. We propose to set-up a systematic framework of projects combining catalyst preparation, in situ and operando characterization, kinetic studies (micro as well as macro-kinetics) with test facilities at different scales and novel reactors, as well as multiscale modeling based on theoretical calculations (density functional theory) and experiments. In this way, we envision to gain access to performance descriptors for more active and selective catalyst states and reaction conditions, where information gained in e- HP may assist in the systematic design of efficient catalysts in t-HP and vice versa. This research unit focuses on the reduction of oxygen to hydrogen peroxide due to the similarities in reaction conditions and employed catalytic materials. Our expectations are, however, that the knowledge and concepts to bridge these two areas that we will develop herein, will be transferable to other thermo- and electro-catalytic reactions such as carbon dioxide and nitrogen reduction.

• DFG Programme: Research Units
• International Connection: Canada, France

Projects

• Analysis and design of electrochemical interfaces for selective e-HP (Applicant Strasser, Peter )
• Combining short-circuited t-HP and half-reactions e-HP in one continuous flow reactor (Applicant Dittmeyer, Roland )
• Coordination Funds (Applicant Behrens, Silke )
• Detailed reaction kinetics of thermo-catalytic direct hydrogen peroxide synthesis using a CSTR for scale-up and process evaluation (Applicant Sauer, Jörg )
• Multiscale analysis of reaction-transport interactions in e-HP (Applicant Krewer, Ulrike )
• Operando characterization of catalysts during H2O2 synthesis (Applicant Grunwaldt, Jan-Dierk )
• Synthesis, characterization and testing of nanoparticle catalysts (Applicant Behrens, Silke )
• Theoretical studies of t-HP and e-HP using DFT calculations (Applicant Studt, Felix )
• TP5: Microkinetic analysis and operando FTIR of electro-catalysts for e-HP (Applicant Röse, Philipp )

• Spokesperson: Professorin Dr. Silke Behrens