Targeted Synthesis of a Highly Stable Aluminium Phosphonate Metal–Organic Framework Showing Reversible HCl Adsorption

Abstract

A concept for obtaining isoreticular compounds with tri-instead of tetravalent metal cations using highly acidic reaction conditions was developed and successfully applied in a high throughput study using N,N'-piperazinebis(methylenephosphonic acid) (H 4 PMP), that resulted in the discovery of a new porous aluminium phosphonate denoted CAU-60•6 HCl. The high-throughput study was subsequently extended to other trivalent metal ions. Al-CAU-60•6 HCl demonstrates reversible desorption of HCl (18.3 wt % loading) with three distinct compositions observed with zero, four or six HCl molecules per formula unit. Structural changes were followed in detail by powder X-ray diffraction, EDX analysis as well as IR spectroscopy. Rapid desorption of HCl in water within minutes and subsequent adsorption from the gas phase and from aqueous solution are shown. Furthermore, it is possible to adsorb HBr into the guest free Al-CAU-60 framework, demonstrating the high stability of this compound.

Bichloride-based ionic liquids for the merged storage, processing, and electrolysis of hydrogen chloride

“…An attractive complementary approach would be a technique that combines the superior safety profile of hydrochloric acid with the advantageous reactivity and electrochemical properties of gaseous hydrogen chloride. Although ionic liquids ( 23 – 25 ) and metal-organic frameworks ( 26 ) for the reversible absorption of HCl are reported, none of them were used as scalable storages that can directly be used for hydrochlorination reactions and electrolysis. Recently, Geng and coworkers ( 27 ) demonstrated that imidazole-based deep eutectic solvents can be used for the efficient coupling of HCl capture and conversion.…”

Engineering a Local Hydrophilic Environment in Fuel Oil for Efficient Oxidative Desulfurization with Minimum H2O2 Oxidant

“…The tail group may be an inert capping group or a reactive part, which can govern the surface wettability of the modified substrate. Phosphonic acids have been widely utilized in the surface-science due to its ease of synthesis and intensive coordination with metal oxides. , Moreover, the electron structure and surface wettability of modified metal oxides can be precisely adjusted by tail groups of phosphonic acids, such as −OH and −NH 2 . Therefore, employing phosphonic acid to adjust and balance the wettability of carbon-supported molybdenum oxide and gaining a deeper insight into the relationship between the local reaction environment and activity would initiate a new era for the design of ODS catalysts.…”

Visible-Light-Active Titanium Sulfonate Framework for Photocatalytic Organic Synthesis

“…By introducing a hydroxy group in the ortho position of the sulfonate group, −OH and sulfonate O atoms can coordinate with Ti 4+ ions in a chelating manner, thereby enhancing the stability of the framework. The formation of a titanium-phenol functional motif further promotes visible light absorption via LMCT. compared with H 4 DOBDC, the strong acidity of H 4 DOBSC may provide more acid medium to stabilize Ti 4+ ions, which facilitates the growth of single crystals. , …”

“…compared with H 4 DOBDC, the strong acidity of H 4 DOBSC may provide more acid medium to stabilize Ti 4+ ions, which facilitates the growth of single crystals. , …”

“…Our design considerations were as follows: (b) compared with H 4 DOBDC, the strong acidity of H 4 DOBSC may provide more acid medium to stabilize Ti 4+ ions, which facilitates the growth of single crystals. 5,32 As anticipated, we have successfully obtained a new single crystal Ti-MOF (denoted as FIR-138, FIR = Fujian Institute Research) based on H 4 DOBSC ligands. It exhibits a 2-fold interpenetrated srs framework with permanent porosity and stability.…”