Interlayer Ions Control Spin Canting in Low-Dimensional Manganese Trimers in 12R-BaMnO ( = Ce, Pr) Layered Perovskites.

To synthetically target a specific material with select performance, the underlying relationship between structure and function must be understood. For targeting magnetic properties, such understanding is underdeveloped for a relatively new class of layered hexagonal perovskites, the 12R-BaMnO family. Here, we perform a detailed magnetostructural study of the layered hexagonal perovskite materials 12R-BaMnO, where = diamagnetic Ce or paramagnetic ≈ 1/2 Pr.

Establishing ZIF-8 as a reference material for hydrogen cryoadsorption: An interlaboratory study.

Hydrogen storage by cryoadsorption on porous materials has the advantages of low material cost, safety, fast kinetics, and high cyclic stability. The further development of this technology requires reliable data on the H uptake of the adsorbents, however, even for activated carbons the values between different laboratories show sometimes large discrepancies. So far no reference material for hydrogen cryoadsorption is available.

Multivariate Flexible Framework with High Usable Hydrogen Capacity in a Reduced Pressure Swing Process.

Step-shaped adsorption-desorption of gaseous payloads by flexible metal-organic frameworks can facilitate the delivery of large usable capacities with significantly reduced energetic penalties. This is desirable for the storage, transport, and delivery of H, as prototypical adsorbents require large swings in pressure and temperature to achieve usable capacities approaching their total capacities. However, the weak physisorption of H typically necessitates undesirably high pressures to induce the framework phase change.

Densified HKUST-1 Monoliths as a Route to High Volumetric and Gravimetric Hydrogen Storage Capacity.

We are currently witnessing the dawn of hydrogen (H) economy, where H will soon become a primary fuel for heating, transportation, and long-distance and long-term energy storage. Among diverse possibilities, H can be stored as a pressurized gas, a cryogenic liquid, or a solid fuel adsorption onto porous materials. Metal-organic frameworks (MOFs) have emerged as adsorbent materials with the highest theoretical H storage densities on both a volumetric and gravimetric basis.

Formation of 6H-BaCeMnO during Thermochemical Reduction of 12R-BaCeMnO: Identification of a Polytype in the Ba(Ce,Mn)O Family.

The resurgence of interest in a hydrogen economy and the development of hydrogen-related technologies has initiated numerous research and development efforts aimed at making the generation, storage, and transportation of hydrogen more efficient and affordable. Solar thermochemical hydrogen production (STCH) is a process that potentially exhibits numerous benefits such as high reaction efficiencies, tunable thermodynamics, and continued performance over extended cycling. Although CeO has been the de facto standard STCH material for many years, more recently 12R-BaCeMnO (BCM) has demonstrated enhanced hydrogen production at intermediate H/HO conditions compared to CeO, making it a contender for large-scale hydrogen production.

Structural resolution and mechanistic insight into hydrogen adsorption in flexible ZIF-7.

Flexible metal-organic frameworks offer a route towards high useable hydrogen storage capacities with minimal swings in pressure and temperature step-shaped adsorption and desorption profiles. Yet, the understanding of hydrogen-induced flexibility in candidate storage materials remains incomplete. Here, we investigate the hydrogen storage properties of a quintessential flexible metal-organic framework, ZIF-7.

Fine-Tuning a Robust Metal-Organic Framework toward Enhanced Clean Energy Gas Storage.

The development of adsorbents with molecular precision offers a promising strategy to enhance storage of hydrogen and methane─considered the fuel of the future and a transitional fuel, respectively─and to realize a carbon-neutral energy cycle. Herein we employ a postsynthetic modification strategy on a robust metal-organic framework (MOF), MFU-4l, to boost its storage capacity toward these clean energy gases. MFU-4l-Li displays one of the best volumetric deliverable hydrogen capacities of 50.

Cubes to Cubes: Organization of MgO Particles into One-Dimensional and Two-Dimensional Nanostructures.

Developing simple, inexpensive, and environmentally benign approaches to integrate morphologically well-defined nanoscale building blocks into larger high surface area materials is a key challenge in materials design and processing. In this work, we investigate the fundamental surface phenomena between MgO and water (both adsorption and desorption) with particles prepared via a vapor-phase process (MgO nanocubes) and a modified aerogel process (MgO(111) nanosheets). Through these studies, we unravel a strategy to assemble individual MgO nanoparticles into extended faceted single-crystalline MgO nanosheets and nanorods with well-defined exposed surfaces and edges.

Carbon Capture by Metal Oxides: Unleashing the Potential of the (111) Facet.

Solid metal oxides for carbon capture exhibit reduced adsorption capacity following high-temperature exposure, due to surface area reduction by sintering. Furthermore, only low-coordinate corner/edge sites on the thermodynamically stable (100) facet display favorable binding toward CO, providing inherently low capacity. The (111) facet, however, exhibits a high concentration of low-coordinate sites.

Exceptional Oxygen Reduction Reaction Activity and Durability of Platinum-Nickel Nanowires through Synthesis and Post-Treatment Optimization.

For the first time, extended nanostructured catalysts are demonstrated with both high specific activity (>6000 μA cm at 0.9 V) and high surface areas (>90 m g ). Platinum-nickel (Pt-Ni) nanowires, synthesized by galvanic displacement, have previously produced surface areas in excess of 90 m g , a significant breakthrough in and of itself for extended surface catalysts.

Synthesis of a mixed-valent tin nitride and considerations of its possible crystal structures.

Recent advances in theoretical structure prediction methods and high-throughput computational techniques are revolutionizing experimental discovery of the thermodynamically stable inorganic materials. Metastable materials represent a new frontier for these studies, since even simple binary non-ground state compounds of common elements may be awaiting discovery. However, there are significant research challenges related to non-equilibrium thin film synthesis and crystal structure predictions, such as small strained crystals in the experimental samples and energy minimization based theoretical algorithms.