ZnPd/ZnO Aerogels as Potential Catalytic Materials

Abstract

Many different aerogel materials are known to be accessible via the controlled destabilization of the respective nanoparticle suspensions. Especially for applications in heterogeneous catalysis such materials with high specific surface areas are highly desirable. Here, a facile method to obtain a mixed ZnPd/ZnO aerogel via a reductive treatment of a preformed Pd/ZnO aerogel is presented. Different morphologies of the Pd/ZnO aerogels could be achieved by controlling the destabilization of the ZnO sol. All aerogels show a high CO2 selectivity of up to 96% and a very good activity in methanol steam reforming that delivers hydrogen, which is one of the most important fuels for future energy concepts. The method presented is promising for different transition metal/metal oxide systems and hence opens a path to a huge variety of materials

Modern Inorganic Aerogels

“…[149] Moreover,t he hierarchically structured MnO 2 aerogels can be used as electrodes in Li-O 2 batteries,a nd display great potential as catalysts for ORR and OER. [150] Starting with astable colloidal solution of ZnO nanoparticles in ethanol, as ponge-like network could be achieved by adding an oxidizing agent, and two-dimensional structures (ribbons and flakes) by adding water (see Figure 21). [150] Starting with astable colloidal solution of ZnO nanoparticles in ethanol, as ponge-like network could be achieved by adding an oxidizing agent, and two-dimensional structures (ribbons and flakes) by adding water (see Figure 21).…”

“…[145] Recently it was possible to control the network morphology of the final aerogel by different destabilization routes. [150] Starting with astable colloidal solution of ZnO nanoparticles in ethanol, as ponge-like network could be achieved by adding an oxidizing agent, and two-dimensional structures (ribbons and flakes) by adding water (see Figure 21). While the first strategy is well known for controlled destabilization and has been presented several times,the second approach is novel.…”

Moderne Anorganische Aerogele

“…[149] Weiterhin kçnnen MnO 2 -Aerogele als Elektroden in Li-O 2 -Batterien genutzt werden und haben ein großes Potential als Katalysatoren fürd ie Sauerstoffreduktions-(ORR) und Sauerstoffentwicklungsreaktion (OER). [150] Ausgehend von einer stabilen, kolloidalen Lçsung von ZnO-Nanopartikeln in Ethanol konnten ein schwammartiges Netzwerk durch Zugabe eines Oxidationsmittels sowie zweidimensionale Strukturen (Bänder und Plättchen) durch Versetzen mit Wasser erhalten werden (Abbildung 21). [150] Ausgehend von einer stabilen, kolloidalen Lçsung von ZnO-Nanopartikeln in Ethanol konnten ein schwammartiges Netzwerk durch Zugabe eines Oxidationsmittels sowie zweidimensionale Strukturen (Bänder und Plättchen) durch Versetzen mit Wasser erhalten werden (Abbildung 21).…”

“…[145] Mithilfe unterschiedlicher Destabilisierungsverfahren war es vor kurzem mçglich, die Netzwerkmorphologie der finalen Aerogele zu kontrollieren. [150]…”

Corrosion‐Free EMF Measurements of Zinc‐Based Intermetallic Compounds at Ambient Temperature

“…[5] The formation of partially very broad homogeneity ranges of the intermetallic compounds (realized by substitution, filling of interstitial spaces of the surplus type of atom or by voids of the subordinate type of atom) also offer the possibility of changing the electronic structure of an intermetallic compound while largely retaining the geometric structure, whereby a separate analysis of the influence by changing the electronic structure of an intermetallic compound becomes accessible. The enormous potential of intermetallic compounds for knowledge-based catalysis research is illustrated by examples such as the development of non-precious metal catalyst materials for the semi-hydrogenation of acetylene, [6] the development of stable and highly active catalysts for methanol steam reforming (MSR) [7] as well as their broad use in electrocatalysis. [8] Interest has been high concerning the intermetallic compounds in the PdÀ Zn system.…”