The Surge of Metal–Organic-Framework (MOFs)-Based Electrodes as Key Elements in Electrochemically Driven Processes for the Environment

Metal–organic-frameworks (MOFs) are emerging materials used in the environmental electrochemistry community for Faradaic and non-Faradaic water remediation technologies. It has been concluded that MOF-based materials show improvement in performance compared to traditional (non-)faradaic materials. In particular, this review outlines MOF synthesis and their application in the fields of electron- and photoelectron-Fenton degradation reactions, photoelectrocatalytic degradations, and capacitive deionization physical separations. This work overviews the main electrode materials used for the different environmental remediation processes, discusses the main performance enhancements achieved via the utilization of MOFs compared to traditional materials, and provides perspective and insights for the further development of the utilization of MOF-derived materials in electrified water treatment

Molecular Insight into Fluorocarbon Adsorption in Pore Expanded Metal–Organic Framework Analogs

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Hierarchically Porous Carbon Materials for CO₂ Capture: The Role of Pore Structure

With advances in porous carbon synthesis techniques, hierarchically porous carbon (HPC) materials are being utilized as relatively new sorbents for CO₂ capture applications. These HPC materials were used as a platform to prepare samples with differing textural properties and morphologies to elucidate structure–property relationships. It was found that high microporous content, rather than overall surface area, was of primary importance for predicting good CO₂ capture performance. Two HPC materials were analyzed, each with near identical high surface area (∼2700 m²/g) and colossally high pore volume (∼10 cm³/g), but with different microporous content and pore size distributions, which led to dramatically different CO₂ capture performance. Overall, large pore volumes obtained from distinct mesopores were found to significantly impact adsorption performance. From these results, an optimized HPC material was synthesized that achieved a high CO₂ capacity of ∼3.7 mmol/g at 25 °C and 1 bar

Dynamic Adsorption of CO₂/N₂ on Cation-Exchanged Chabazite SSZ-13: A Breakthrough Analysis

Alkali-exchanged SSZ-13 adsorbents were investigated for their applicability in separating N₂ from CO₂ in flue gas streams using a dynamic breakthrough method. In contrast to IAST calculations based on equilibrium isotherms, K⁺ exchanged SSZ-13 was found to yield the best N₂ productivity, comparable to Ni-MOF-74, under dynamic conditions where diffusion properties play a significant role. This was attributed to the selective, partial blockage of access to the chabazite cavities, enhancing the separation potential in a 15/85 CO₂/N₂ binary gas mixture

An Efficient, Solvent-Free Process for Synthesizing Anhydrous MgCl₂

A new efficient and solvent-free method for the synthesis of anhydrous MgCl₂ from its hexahydrate is presented. Fluidized dehydration of MgCl₂·6H₂O feedstock at 200 °C in a porous bed reactor yields MgCl₂·nH₂O (0 < n < 1), which has a similar diffraction pattern as activated MgCl₂. The MgCl₂·nH₂O is then ammoniated directly using liquefied NH₃ in the absence of solvent to form MgCl₂·6NH₃. Calcination of the hexammoniate complex at 300 °C then yields anhydrous MgCl₂. Both dehydration and deammoniation were thoroughly studied using <i>in situ</i> as well as <i>ex situ</i> characterization techniques. Specifically, a detailed understanding of the dehydration process was monitored by <i>in situ</i> PXRD and <i>in situ</i> FTIR techniques where formation of salt with nH₂O (n = 4, 2, 1, <1) was characterized. Given the reduction in thermal energy required to produce dehydrated feedstock with this method compared with current strategies, significant cost benefits are expected. Overall, the combined effect of activation, macroporosity, and coordinated water depletion allows the formation of hexammoniate without using solvent, thus minimizing waste formation