Aerogels in gas phase catalysis

A high porosity and a large specific surface area not only characterizes aerogels as special materials, but are also found in most heterogeneous catalysts. Therefore, it suggests itself to combine the two topics. As a substance-unspecific class of materials, a wide variety of materials can be produced as aerogels, which opens the way to a large number of catalyst systems and reactions. We were able to demonstrate this together with our cooperation partner, the group of Prof. Marc Armbrüster at the TU Chemnitz, using the complex example of transferring several mixed oxide - intermetallic phase systems to aerogels. By a straightforward one-pot synthesis, the basic building block of the aerogels is laid here, which are prepared for catalysis by further activation steps. The nanoscale individual building blocks of the macroscopic aerogel provide high atomic efficiency and a large cross-sectional area for the two components involved in catalysis. In addition to the characterization and synthesis of the aerogels and their catalytic behavior, the observation of phases forming in the gel matrix and the stability in the reactor in comparison to existing catalyst systems or the bulk materials are particularly exciting. Using the above mentioned principles, highly selective and active aerogel catalysts for methanol steam reforming were successfully produced.

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• Ziegler, C.; Klosz, S.; Borchardt, L.; Oschatz, M.; Kaskel, S.; Friedrich, M.; Kriegel, R.; Keilhauer, T.; Armbrüster, M.; Eychmüller, A. ZnPd/ZnO Aerogels as Potential Catalytic Materials. Adv. Funct. Mater. 2016, 26 (7), 1014–1020. https://doi.org/10.1002/adfm.201503000.
• Köwitsch, N.; Thoni, L.; Klemmed, B.; Benad, A.; Paciok, P.; Heggen, M.; Köwitsch, I.; Mehring, M.; Eychmüller, A.; Armbrüster, M. Proving a Paradigm in Methanol Steam Reforming: Catalytically Highly Selective InxPdy/In2O3Interfaces. ACS Catal. 2021, 11 (1), 304–312. https://doi.org/10.1021/acscatal.0c04073.
• Köwitsch, N.; Thoni, L.; Klemmed, B.; Benad, A.; Paciok, P.; Heggen, M.; Eychmüller, A.; Armbrüster, M. Unprecedented Catalytic Activity and Selectivity in Methanol Steam Reforming by Reactive Transformation of Intermetallic In–Pt Compounds. J. Phys. Chem. C 2021, 125 (18), 9809–9817. https://doi.org/10.1021/acs.jpcc.1c02260.