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Mixed matrix membranes (MMMs) have emerged as promising materials for various separation processes due to their tunable properties, enhanced separation performance and reproducibility. In this review paper, we provide a comprehensive overview of the methodologies, challenges, and applications associated with the characterization of MMMs using two advanced imaging techniques: Focused Ion Beam Scanning Electron Microscopy (FIB‐SEM) and Transmission Electron Microscopy (TEM). We begin by outlining the principles and capabilities of FIB‐SEM and TEM, emphasizing their suitability for studying the microstructure, morphology, and composition of MMMs at nanoscale resolution. Subsequently, we discuss the specific challenges and limitations encountered in the characterization of MMMs using these techniques, including sample preparation, image acquisition, and data interpretation. Furthermore, we review the diverse applications of FIB‐SEM and TEM in elucidating the structure‐property relationships of MMMs. Through illustrative examples, we highlight the valuable insights gained from these imaging techniques in optimizing MMMs for various separation applications. Finally, we propose future directions and emerging trends in MMM characterization, including the integration of lasers into FIB‐SEM and in situ characterization techniques, to address current challenges and push the boundaries of MMM design and performance. Overall, this review provides a comprehensive overview of the state‐of‐the‐art methodologies for characterizing MMMs using FIB‐SEM and TEM, identifies key challenges, and offers insights into future research directions aimed at harnessing the full potential of MMMs for sustainable separation technologies. [ABSTRACT FROM AUTHOR]

The zeolite‐catalyzed methanol‐to‐aromatics (MTA) process is a promising avenue for industrial decarbonization. This process predominantly utilizes 3‐dimensional 10‐member ring (10‐MR) zeolites like ZSM‐5 and ZSM‐11, chosen for their confinement effect essential for aromatization. Current research mainly focuses on enhancing selectivity and mitigating catalyst deactivation by modulating zeolites′ physicochemical properties. Despite the potential, the MTA technology is at a low Technology Readiness Level, hindered by mechanistic complexities in achieving the desired selectivity towards liquid aromatics. To bridge this knowledge gap, this study proposes a roadmap for MTA catalysis by strategically combining controlled catalytic experiments with advanced characterization methods (including operando conditions and "mobility‐dependent" solid‐state NMR spectroscopy). It identifies the descriptor‐role of Koch‐carbonylated intermediates, longer‐chain hydrocarbons, and the zeolites′ intersectional cavities in yielding preferential liquid aromatics selectivity. Understanding these selectivity descriptors and architectural impacts is vital, potentially advancing other zeolite‐catalyzed emerging technologies. [ABSTRACT FROM AUTHOR]

The direct liquid‐phase oxidative carbonylation of methane, utilizing abundant natural gas, offers a mild and straightforward alternative. However, most catalysts proposed for this process suffer from low acetic acid yields due to few active sites and rapid C1 oxygenate generation, impeding their industrial feasibility. Herein, we report a highly efficient 0.1Cu/Fe‐HZSM‐5‐TF (TF denotes template‐free synthesis) catalyst featuring exclusively mononuclear Fe and Cu anchored in the ZSM‐5 channels. Under optimized conditions, the catalyst achieved an unprecedented acetic acid yield of 40.5 mmol gcat−1 h−1 at 50 °C, tripling the previous records of 12.0 mmol gcat−1 h−1. Comprehensive characterization, isotope‐labeled experiments and density functional theory (DFT) calculations reveal that the homogeneous mononuclear Fe sites are responsible for the activation and oxidation of methane, while the neighboring Cu sites play a key role in retarding the oxidation process, promoting C−C coupling for effective acetic acid synthesis. Furthermore, the methyl‐group carbon in acetic acid originates solely from methane, while its carbonyl‐group carbon is derived exclusively from CO, rather than the conversion of other C1 oxygenates. The proposed bimetallic catalyst design not only overcomes the limitations of current catalysts but also generalizes the oxidative carbonylation of other alkanes, demonstrating promising advancements in sustainable chemical synthesis. [ABSTRACT FROM AUTHOR]

Photo-thermal carbon dioxide (CO2) reduction has recently gained significant attention as a strategy to harness solar energy and address environmental challenges. Among other photo-thermal catalysts, indium oxide (In2O3) has emerged as a promising candidate for the CO2 hydrogenation reaction. However, owing to its wide band gap semiconductor nature and relatively low CO2 adsorption capacity, modifications are imperative to facilitate efficient light absorption and CO2 activation. In this study, we report alkali-promoted In2O3 catalysts for efficient and selective photo-thermal CO2 hydrogenation to carbon monoxide (CO). By virtue of the enhanced CO2 adsorption capacity, Cs-promoted In2O3 demonstrated superior catalytic performance with a CO production rate of 28 mmol g−1 h−1 and 100% selectivity under full solar spectrum irradiation and without external heating, which is more than 3 times higher compared to that of pure In2O3. Mechanistic studies indicated that non-thermal effects dominate the reaction pathway, particularly at low reaction temperatures and high light intensities, accompanied by minor pure thermal effects. Additional experiments revealed that the in situ formation of defective sites on the indium oxide catalyst surface under illumination could enhance the light absorption ability, thereby significantly enhancing CO production. Diffuse-reflectance infrared Fourier transform spectroscopy (DRIFTS) demonstrated that light irradiation could stabilize key reaction intermediates and accelerate the CO2 hydrogenation reaction at low temperatures, ultimately boosting CO production compared to dark conditions. [ABSTRACT FROM AUTHOR]

Herein we present the first example of a glycol-coordinated ε-Keggin Al13 chloride (gl-ε-Al13), which is the first chelated version since discovery of Al13 in 1960. The molecular structure consists of [AlO4Al12(OH)12(OC2H4OH)12]Cl7·H2O units with chelating mono-anionic ethylene glycol units replacing one bridging and one terminal oxygen site.

Herein we present the first example of a glycol-coordinated ε-Keggin Al13 chloride (gl-ε-Al13), which is the first chelated version since discovery of Al13 in 1960. The molecular structure consists of [AlO4Al12(OH)12(OC2H4OH)12]Cl7·H2O units with chelating mono-anionic ethylene glycol units replacing one bridging and one terminal oxygen site.

In the context of advancing social modernization, the projected shortfall in the demand for renewable aromatic hydrocarbons is expected to widen, influenced by industries like high-end materials, pharmaceuticals, and consumer goods. Sustainable methods for aromatic production from alternative sources, particularly the methanol-to-aromatics (MTA) process using zeolite ZSM-5 and associated with the "methanol economy", have garnered widespread attention. To facilitate this transition, our project consolidates conventional strategies that impact aromatics selectivity—such as using hierarchical zeolites, metallic promoters, or altering zeolite physicochemical properties—into a unified study. Our findings demonstrate the beneficial impact of elongated crystal size and heightened zeolite hierarchy on preferential aromatics selectivity, albeit through distinct mechanisms involving the consumption of shorter olefins. While metallic promoters enhance MTA performance, crystal size, and hierarchy remain pivotal in achieving the maximized aromatics selectivity. This study contributes to a deeper understanding of achieving superior aromatics selectivity through physicochemical modifications in zeolite ZSM-5 during MTA catalysis, thereby advancing the field's comprehension of structure–reactivity relationships. [ABSTRACT FROM AUTHOR]