Proving a Paradigm in Methanol Steam Reforming: Catalytically Highly Selective In<sub><i>x</i></sub>Pd<sub><i>y</i></sub>/In<sub>2</sub>O<sub>3</sub> Interfaces
Nicolas Köwitsch, Lukas Thoni, Benjamin Klemmed, Albrecht Benad, Paul Paciok, Marc Heggen, Isabel Köwitsch, Michael Mehring, Alexander Eychmüller, Marc Armbrüster
Abstract
Methanol steam reforming provides clean hydrogen by onboard production, which can directly be used for fuel cell applications–while using appropriate catalysts. InxPdy/In2O3 aerogels exhibit excellent CO2 selectivities of 99%. This is caused by the active participation of chemically bound oxygen from the material as proven by isotope-labeling experiments. In addition, the dynamic, temperature-dependent equilibrium between intermetallic and oxidic species has a strong impact on the catalytic properties of the material. Thus, the intermetallic compounds in close proximity to a supporting reducible oxide act as selectivity-decisive redox centers, enabling a Mars-van Krevelen mechanism, which is responsible for the excellent selectivity toward CO2.