Random organic framework membranes with hierarchical channels for H₂ separation

Novel membrane materials for H₂ separation are wanted. How to overcome the “trade-off” between membrane permeability and selectivity is a tough challenge. Here we report new random organic framework membranes with benzimidazole and imine linkages to form hierarchical channels. Both high H₂-selective and fast H<sub>2</sub...

Water Adsorption in MOFs: Structures and Applications

Metal–organic frameworks (MOFs) are superior sorbents for water adsorption-based applications. The unique step-like water isotherm at a MOF-specific relative pressure allows easy loading and regeneration over a small range of temperature and pressure conditions. With good hydrothermal stability and cyclic durability, it stands out over...

Zeolite membranes – The importance of support analysis

Zeolite membranes are highly attractive in energy efficient, selective separation technologies. Their high selectivity originates from selective adsorption, diffusion and even molecular sieving. High flux zeolite membranes (&gt; 1 mol s⁻¹m⁻²) with a sub-micrometer thickness are mechanically stabilized by a porous, often...

High-Silica CHA Zeolite Membrane with Ultra-High Selectivity and Irradiation Stability for Krypton/Xenon Separation

Capture and storage of the long-lived ⁸⁵Kr is an efficient approach to mitigate the emission of volatile radionuclides from the spent nuclear fuel reprocessing facilities. However, it is challenging to separate krypton (Kr) from xenon (Xe) because of the chemical inertness and similar physical properties. Herein we prepared high...

Highly Water-Permeable Metal-Organic Framework MOF-303 Membranes for Desalination

New membrane materials with excellent water permeability and high ion rejection are needed. Metal-organic frameworks (MOFs) are promising candidates by virtue of their diversity in chemistry and topology. In this work, continuous aluminum MOF-303 membranes were prepared on α-Al2O3 substrates via an in situ hydrothermal synthesis method. The...

Water and Metal-Organic Frameworks: From Interaction toward Utilization

The steep stepwise uptake of water vapor and easy release at low relative pressures and moderate temperatures together with high working capacities make metal-organic frameworks (MOFs) attractive, promising materials for energy efficient applications in adsorption devices for humidity control (evaporation and condensation processes) and heat...

Novel high performance poly(p-phenylene benzobisimidazole) (PBDI) membranes fabricated by interfacial polymerization for H 2 separation

Membranes with high selectivity and permeance are needed to reduce energy consumption in hydrogen purification and pre-combustion CO ₂ capture. Polybenzimidazole (PBI) is one of the leading membrane materials for this separation. In this study, we present superior novel supported PBI (poly(p-phenylene benzobisimidazole), PBDI)...

High-performance polybenzimidazole membranes for helium extraction from natural gas

Increasing helium use in research and production processes necessitates separation techniques to secure sufficient supply of this noble gas. Energy-efficient helium production from natural gas is still a big challenge. Membrane gas separation technology could play an important role. Herein, a novel poly(p-phenylene benzobisimidazole) (PBDI)...

Engineering Metal–Organic Frameworks for the Electrochemical Reduction of CO₂: A Minireview

The electrochemical reduction of CO₂ holds great promise for lowering the concentration of CO₂ in the Earth′s atmosphere. However, several challenges have hindered the commercialization of this technology, including energy efficiency, the solubility of CO₂ in the aqueous phase, and electrode stability. In this...

Structure-activity relationships in metal organic framework derived mesoporous nitrogen-doped carbon containing atomically dispersed iron sites for CO₂ electrochemical reduction

Mesoporous nitrogen-doped carbon nanoparticles with atomically dispersed iron sites (named mesoNC-Fe) are synthesized via high-temperature pyrolysis of an Fe containing ZIF-8 MOF. Hydrolysis of tetramethyl orthosilicate (TMOS) in the MOF framework prior to pyrolysis plays an essential role in maintaining a high surface area during the...

Maximizing Ag Utilization in High-Rate CO₂ Electrochemical Reduction with a Coordination Polymer-Mediated Gas Diffusion Electrode

We report the preparation and electrocatalytic performance of silver-containing gas diffusion electrodes (GDEs) derived from a silver coordination polymer (Ag-CP). Layer-by-layer growth of the Ag-CP onto porous supports was applied to control Ag loading. Subsequent electro-decomposition of the Ag-CP resulted in highly selective and efficient...

NO_x reduction in the Di-Air system over noble metal promoted ceria

In this study, the role of the noble metals Pt and Rh (0.5 wt.%) for the selective reduction of NO into N₂ is evaluated by the transient TAP technique and in-situ spectroscopy using a commercial stable ceria support (denoted as CZ) and applying isotopically labelled ¹⁵NO and ¹⁸O₂. The transient...

Molecular-Scale Hybrid Membranes Derived from Metal-Organic Polyhedra for Gas Separation

The preparation and the performance of mixed matrix membranes based on metal-organic polyhedra (MOPs) are reported. MOP fillers can be dispersed as discrete molecular units (average 9 nm in diameter) when low filler cargos are used. In spite of the low doping amount (1.6 wt %), a large performance enhancement in permeability, aging resistance...

Metal-Organic-Framework-Mediated Nitrogen-Doped Carbon for CO₂ Electrochemical Reduction

A nitrogen-doped carbon was synthesized through the pyrolysis of the well-known metal-organic framework ZIF-8, followed by a subsequent acid treatment, and has been applied as a catalyst in the electrochemical reduction of carbon dioxide. The resulting electrode shows Faradaic efficiencies to carbon monoxide as high as ∼78%, with hydrogen...

Facile manufacture of porous organic framework membranes for precombustion CO₂ capture

The development of new membranes with high H₂ separation performance under industrially relevant conditions (high temperatures and pressures) is of primary importance. For instance, these membranes may facilitate the implementation of energy-efficient precombustion CO₂ capture or reduce energy intensity in other...

Benzimidazole linked polymers (BILPs) in mixed-matrix membranes: Influence of filler porosity on the CO₂/N₂ separation performance

The performance of mixed-matrix membranes (MMMs) based on Matrimid^® and benzimidazole-linked polymers (BILPs) have been investigated for the separation CO₂/N₂ and the dependency on the filler porosity. BILPs with two different porosities (BILP-101 and RT-BILP-101) were synthesized through controlling the...

Fundamental Understanding of the Di-Air System: The Role of Ceria in NO_x Abatement

Temporal analysis of product (TAP) is used to investigate the effectiveness of CO, C₃H₆, and C₃H₈ in the reduction of a La–Zr doped ceria catalyst and NO reduction into N₂ over this pre-reduced catalyst. Hydrocarbons are found to be substantially more effective in the reduction of this...