There is currently intense research on sulfur/carbon composite materials as positive electrodes for rechargeable batteries. Such composites are commonly prepared by ball milling or (melt/solution) impregnation to achieve intimate contact between both elements with the hope to improve battery performance. Herein, we report that sulfur shows an unexpected "spillover" effect when in contact with porous carbon materials under ambient conditions. When sulfur and porous carbon are gently mixed in a 1:1 mass ratio, complete surface coverage takes place within just a few days along with the loss of the sulfur bulk properties (crystallinity, melting point, Raman signals). Sulfur spillover also occurs in the presence of a liquid phase. Consequences of this phenomenon are discussed by considering a sodium-sulfur cell with a solid electrolyte membrane.

Methanol steam reforming provides clean hydrogen by onboard production, which can directly be used for fuel cell applications−while using appropriate catalysts. In x Pd y /In 2 O 3 aerogels exhibit excellent CO 2 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 CO 2 .

Ultrathin layers of oxides deposited on atomically flat metal surfaces have been shown to significantly influence the electronic structure of the underlying metal, which in turn alters the catalytic performance. Upscaling of the specifically designed architectures as required for technical utilization of the effect has yet not been achieved. Here, we apply liquid crystalline phases of fluorohectorite nanosheets to fabricate such architectures in bulk. Synthetic sodium fluorohectorite, a layered silicate, when immersed into water spontaneously and repulsively swells to produce nematic suspensions of individual negatively charged nanosheets separated to more than 60 nm, while retaining parallel orientation. Into these galleries oppositely charged palladium nanoparticles were intercalated whereupon the galleries collapse. Individual and separated Pd nanoparticles were thus captured and sandwiched between nanosheets. As suggested by the model systems, the resulting catalyst performed better in the oxidation of carbon monoxide than the same Pd nanoparticles supported on external surfaces of hectorite or on a conventional Al2O3 support. XPS confirmed a shift of Pd 3d electrons to higher energies upon coverage of Pd nanoparticles with nanosheets to which we attribute the improved catalytic performance. DFT calculations showed increasing positive charge on Pd weakened CO adsorption and this way damped CO poisoning.

Hydrogen storage in the form of small molecules and subsequent release are foreseen to play a fundamental role in future energy systems or carbon cycles. Methanol is an ideal hydrogen carrier due to the high H/C ratio, the lack of C–C bonds, and being liquid under ambient conditions. Methanol steam reforming is an advantageous reaction for the release of the chemically bound hydrogen. Pd- or Pt-based intermetallic compounds have shown to be CO2-selective and long-term stable catalytic materials. However, an intrinsic understanding of the underlying processes is still lacking. In this study, we show that the redox activity in the In–Pt system can be steered by gas-phase changes and leads to highly active catalytic materials at 300 °C [1500 mol (H2)/(mol (Pt) × h)] with an excellent CO2 selectivity of 99.5%, thus clearly outperforming previous materials. Reactive transformations between In2Pt, In3Pt2, and In2O3 have been identified to cause the high selectivity. Redox activity of intermetallic compounds as part of the catalytic cycle was previously unknown and adds an understanding to the concept of different adsorption sites.

The adaption of the sol-gel autocombustion method to the Cu/ZrO2 system opens new pathways for the specific optimisation of the activity, long-term stability and CO2 selectivity of methanol steam reforming...