The power-to-methanol (PtMeOH) will play a crucial role as a form of renewable chemical energy storage. In this paper, PtMeOH techno-economics are assessed using the promising configuration from the previous work (Mbatha et al. [1]). This study evaluated the effect of parameters such as the CO2 emission tax, electricity price, and CAPEX reduction on the product methanol economic parity with respect to a reference case. Superior to previous economic studies, a scenario where an existing methanol synthesis infrastructure is 100 % retrofitted with the promising electrolyser is assessed in terms of its economics and the associated economic parity. The volatile South African electricity market is considered as a case study. The sensitivity of the PtMeOH and green H-2 profitability are checked. Grid-connected and standalone renewable energy PtMeOH scenarios are assessed. Foremost, generalisable effect trends of these parameters on the net present value (NPV) and the levelized cost of methanol(LCOMeOH) and H-2 (LCOH2) are discussed. The results show that economic parity of H-2 (LCOH2 = current selling price = 4.06 /kg) can be reached with an electricity price of 30 /MWh and 70 % of the CAPEX. While the LCOMeOH will still be above 2 /kg at 80 % of the CAPEX and electricity price of 20 /MWh. This indicates that even if the CAPEX reduces to 20 % of its original in this study, and the electricity price reduces to about 20 /MWh, the LCOMEOH will still not reach economic parity (LCOMeOH > current selling price = 0.44 /kg). The results show that to make the retrofitted plant, with a minimum of 20 years of life span, profitable, a feasible reduction in the electricity price to below 10 /MWh along with favourable incentives such as CO2 credit and reduction in CAPEX, particularly that of the electrolyser, and treatment of the PtMeOH as a multiproduct plant will be required.

Sorption enhanced reaction processes (SERP) were successfully evaluated in the CO2 hydrogenation reaction, by leveraging the sorption benefits to enhance the formation of methanol. In this work, a dedicated experimental protocol and an analytical setup were developed to quantitatively investigate the coupling between reaction and sorption during the transient regime. This system enables the direct quantification of all molecules at the reactor outlet, including methanol and water, thus allowing an accurate real-time mass balance analysis and improved understanding of the phenomena occurring during sorption-enhanced operation.Experiments performed at 230 °C and 30 bar using a Cu / ZnO / Al2O3 commercial catalyst combined with LTA zeolite (4A) demonstrated that sorption significantly enhances methanol production beyond the thermodynamic equilibrium predicted for a conventional reactor, while the impact on CO production remains limited. Substantial adsorption of both water and methanol within the zeolite framework was assessed. Indeed, the LTA sorbent exhibited a methanol sorption selectivity of 31%, which significantly enhanced the total methanol production during the sorption-enhanced effect. Indeed, 56% of the total methanol formed was temporarily retained within the zeolite, highlighting the key role of the methanol sorption in promoting CO2 hydrogenation with respect to the reverse water-gas shift reaction (RWGS), while water removal influences both reactions. As a result of this sorption-enhanced effect, the quantities of methanol and CO produced increased by 168% and 55%, respectively, compared with the reference experiment for a 60 min period. Structural characterization (XRD and 27Al MAS NMR) confirmed that the LTA zeolite framework remained stable after the experiment despite the harsh conditions of high pressure and temperature in the presence of steam.

Two new pillared-layer mixed-ligand metal-organic frameworks (MOFs) were synthesized using 2,5-thiophene dicarboxylic acid (TDC) in combination with pyrazine (Pyr) or 1,4-diazabicyclo[2.2.2]octane (DABCO). Copper, positioned between hard and soft acids according to the HSAB theory, was selected as the metal center. Pairing the anionic carboxylate linker with neutral N-donor ligands yielded a 3D framework in the TDC-Pyr system and a 2D architecture in the TDC-DABCO system. Both materials exhibited structural phase transformations at approximately 200 degrees C. The MOFs were fully characterized by SCXRD, PXRD, FT-IR, TGA, nitrogen physisorption analyses, and CO2 sorption studies. Notably, the 2D Cu-TDC-DABCO framework achieved the highest CO2 uptake, reaching 2.5 mmol g-1 at 273 K and 1.2 bar.

This study focuses on the rational design and synthesis of sucrose-derived nitrogen-doped porous carbon (ACN) materials for enhanced CO2 capture. ACN were synthesized by thermochemical activation of sucrose and characterized by their specific surface area, pore size distribution, XPS analysis, and CO2 adsorption capacities. The carbons showed excellent specific surface areas, with the best value being 2670.7 m² g-1, obtained for ACN (1:1:2). Additionally, depending on the ACN, pore sizes varied between 10 Å and 37 Å. XPS analysis confirmed the successful doping of nitrogen in the carbon, as well as the presence of oxygen in the final material.CO2 capture analysis demonstrated that ACN (1:2:1) exhibits a superior adsorption capacity with a value of 5.8 mmol g-1 at 273 K and 1200 mbar despite the smallest surface area amongst materials (1431 m² g-1). This study underscores the potential of carbon-based materials for CO2 capture application, offering insights into the design principles for optimizing adsorption performance.

This study demonstrates a circular economy approach to carbon dioxide sorption by re-purposing coal fly ash (CFA) into BEA zeolite using CFA-derived nano-silica and aluminum precursors via hydrothermal synthesis. The XRD patterns, with characteristic peaks at 15 degrees and 37 degrees 2 theta, and SEM images both confirmed the complete transformation of the spherical-shaped CFA particles into amorphous nano-silica materials with particle sizes less than 100 nm. The absence of amorphous phases and the formation of high-intensity peaks at 7.8 degrees and 22.8 degrees 2 theta further indicated the production of a highly crystalline BEA zeolite, obtained after hydrothermal synthesis durations between 10 and 72 h. The conversion of amorphous nano-silica into BEA zeolites significantly enhanced the surface area from 54 m(2)/g to 547 m(2)/g. The as-synthesized BEA zeolites exhibit a spheroidal shape with crystal dimensions ranging from 190 to 450 nm, solely controlled by the molar ratio of H2O/Si during hydrothermal synthesis. CO2 sorption capacity upon the transformation of nano-silica into BEA zeolites rose from 0.91 to 3.24 mmol/g for low-temperature evaluation (approximate to 0 degrees C, 1.2 bar). The BEA zeolite adsorbent retained structural integrity with only similar to 9% performance loss after ten adsorption-desorption cycles. These outcomes highlight CFA-derived BEA zeolite as a robust, scalable, and resource-efficient adsorbent for CO2 capture.

Biomass‐assisted synthesis was applied to ZSM‐5 zeolites with Si/Al ratios ranging from 14 to 69, using lignin and lignin–sugarcane bagasse as co‐templates. Biomass addition enhanced yield, crystallinity, and Al incorporation, while reducing crystal size and silanol defects density, consistent with a confined crystal growth. Catalytic tests revealed composition‐ and reaction‐specific effects: Al‐rich samples demonstrated higher activity in n‐hexane cracking and superior performance in methane dehydroaromatization upon Mo loading, whereas Al‐poor and biomass‐modified zeolites exhibited longer lifetimes in the methanol‐to‐olefins (MTO) reaction. These findings demonstrate that biomass‐mediated synthesis offers a versatile route to tailor ZSM‐5 zeolite properties for diverse catalytic applications.

Nanosized EMT/FAU zeolites were synthesized in the purpose of designing a suspension to address a general issue of dampening reactive oxygen species (ROS) produced in multiple pathologies. Zeolites were characterized by SEM, TEM, XRD, and N2 adsorption-desorption measurements. In addition, zeolites were also grafted with amine groups, being either a common mean for surface functionalization of nanoparticles, but also, the causality between amine groups and upregulation of ROS is still a matter of debate. Surface fonctionalization was performed by silanization of zeolites with (3-aminopropyl) triethoxysilane (APTES), yielding to a reduction of specific surface area, to 390 m2/g instead of 620 m2/g for pristine zeolites (control). XPS studies allowed to confirm the successful grafting of amines, while the propensity of zeolites to scavenge or inhibit ROS production was first tested in the Fenton reaction, where the extent of degradation of a probe molecule (i.e. salicylic acid) was evaluated in presence of zeolites. Results show a maximum protection up to 84 % for conditions with control zeolites at 1 mg/mL whilst amine-grafted counter parts exhibit only 34 % protection at the same concentration. In stark contrast, only 16 % protection was found when no zeolite was used, demonstrating a strong effect of surface modification, which was related to both surface chemistry, and available surface area. Lastly, isolated mitochondria from four different tissues, namely, brain, heart, liver, and kidney medulla importantly involved in toxic clearance and/or major physiologica functions were suspended with zeolites, and mitochondrial oxygen consumption and hydrogen peroxide production were measured simultaneously in response to various dose of zeolites (from 0.01 to 1 mg/mL). No significant impairment of mitochondrial respiration could be evidenced, showing a non-harmful effect of zeolites. A trend toward higher levels of hydrogen peroxide could be detected for amine-grafted zeolites in brain and heart mitochondria at higher doses, while no similar trend could be observed for control zeolites. A plausible explaination was mass transport limitations resulting from particle aggregation at high concentrations as shown by DLS. This study therefore shows the ability of nanosized zeolites to alleviate ROS level in a model reaction, and for the first time using isolated mitochondria, an organelle-specific relationship between mitochondrial functions and zeolites functionalization.

Alkali metal-modified M-ZSM-5 zeolites (M: Li+, Na+, K+) were synthesized by cationic exchange and characterized using ICP-MS, XRD, N2 adsorption–desorption, Py-IR and NH3-TPD techniques to evaluate their elemental composition, structure, textural and acidic properties. In addition, XPS and DFT calculations were employed to study the effects of metal ion doping on the electronic structure and catalytic behavior. The latter catalytic performance was assessed in the methanol-to-olefin (MTO) reaction. The results showed that alkali metal doping facilitated the enhancement of the zeolite structural stability, adjustment of acid density, and increase in the adsorption energy of light olefins onto the active sites. During the reaction, olefin products shifted from Brønsted acid sites to alkali metal sites, effectively minimizing hydrogen transfer reactions. This change in the active site nature promoted the olefin cycle, resulting in higher yields in propylene and butylenes, reduced coke deposition, and prolonged catalyst lifetime. Among all zeolites, Li-exchanged ZSM-5 exhibited the best and extending the catalyst lifetime by 5 h.

Abstract This account aims to report the (often) disregarded impact of zeolite crystal morphology, along with its chemical composition, on applications in the health sector. In recent years, a few groups have developed several strategies to better control zeolite crystal size as well as crystal habit. We have therefore been tempted to select and give an overview of those seminal studies, with the hope that they can serve as a source of inspiration for researchers to design new porous materials for different sectors of applications. To open the way, we are focusing our study on emerging applications related to the biomedical sector.

This study focuses on the exchange of mono- and divalent metal cations in FAU-type zeolite and their behavior in gas-phase CO2 adsorption measurements and liquid-phase methylene blue (MB) adsorption in the absence of oxidizing agents under dark conditions. Firstly, zeolites exchanged with different cations were characterized by several techniques, such as XRD, SEM, XRF, XPS, and N2 adsorption–desorption, to reveal the impact of the cations on the zeolite texture and structure. The adsorption studies revealed a positive effect of cation exchange on the adsorption capacity of the zeolite, particularly for silver-loaded FAU zeolite. In liquid-phase experiments, Ag-Y zeolite also demonstrated the highest MB removal, with a value of 79 mg/g. Kinetic studies highlighted that Ag-Y could reach the MB adsorption equilibrium within 1 h, with its highest rate of adsorption occurring during the first 5 min. In gas-phase adsorption studies, the highest CO2 adsorption capacity was also achieved over Ag-Y, yielding 10.4 µmol/m2 of CO2 captured.

The design of zeolites with optimized textural properties is a continuous goal. Here, we report a composite comprising mesoporous ultra-stable zeolite Y (USY) and nanosized Zeolite Socony Mobil-5 (ZSM-5) with enhanced acid site accessibility and pore connectivity through quasi-in situ interzeolite conversion in a solvent-free medium. The preparation of the composite begins with a spatial and elemental-biased dissolution of USY with impregnated tetrapropylammonium hydroxide (TPAOH). This results in a hierarchical zeolite with increased mesopore volume and improved pore connectivity. Simultaneously, the solute provides all the necessary nutrients for the growth of ZSM-5 zeolite. Due to the constrained mass transfer during the quasi-solid-state dissolution, the resulting ZSM-5 crystals are as small as 10 nm and intimately connected with the USY zeolite. The advantageous synergy between zeolites Y and ZSM-5 in the composite was demonstrated through the methanol-to-olefin reaction and the cracking of n-hexane.

This study evaluates the impact of biomass addition on the physicochemical properties of ZSM-5 zeolites. Three families of zeolites were synthesized hydrothermally: a reference zeolite without biomass, one with lignin, and another combining lignin and sugarcane bagasse. Biomass has been shown to modify the zeolite structure by reducing the crystal size, favouring aluminium incorporation within the framework and reducing the number of defects as internal silanols. These modifications are attributed to the chemical interactions between biomass and inorganic precursors present in solution. The catalytic performance of these zeolites was analysed in n-hexane cracking and in the methanol to olefin (MTO) reactions. Zeolites synthesized with biomass demonstrated improved catalytic stability and selectivity towards light olefins, thanks to an enhanced diffusion path. Lignin, in particular, helped minimize structural defects, thus improving the catalyst lifetime. The addition of biomass offers significant advantages for tailoring zeolite properties while using renewable and abundant resources. This innovative approach opens up interesting prospects for the sustainable design of catalytic materials. It also enables agricultural and industrial wastes to be recycled into high value-added applications, strengthening the links between green chemistry and industrial performance.

A recurring secondary building unit is observed in Ca-MOFs prepared in deep eutectic solvents based on 1 : 2 combinations of choline chloride and urea derivatives.

Coal fly ash and acid mine drainage are significant environmental issues in South Africa, causing storage constraints and impacting water quality. This study explores the use of coal fly ash and acid mine drainage in preparing zeolite HBEA-supported Fe catalysts. The Na-BEA parent catalysts were synthesised hydrothermally using coal fly ash as a feedstock. The Fe was loaded upon the H-BEA form zeolite using liquid-phase ion exchange or wet impregnation, using Fe-rich acid mine drainage as the metal precursor. The ion-exchanged Fe-BEA catalysts exhibited excellent activity, with the highest selectivity achieved over the 25 AHW after 0.5 h on stream. The study also found that when impregnation was used to load Fe onto the zeolite support, other metals present in the AMD affected the overall activity, with Mn, Ca, Mg, and Na decreasing conversion and selectivity, while Ni had a promoting effect. This study demonstrates that green solid acid catalysts with high catalytic activity can be prepared using two waste materials, coal fly ash and acid mine drainage. To the best of our knowledge, we are reporting for the first time the use of acid mine drainage as a metal precursor in Fe-BEA catalyst preparation.

The present study reports the successful synthesis of ZSM-5 zeolites with high external specific surface area by using biochar as a hard template. The physicochemical properties of the biochars (originated from grass, tea and lignin) were studied using XRD, SEM EDX, FTIR and other characterization techniques. The results showed that biochars obtained from different plants, due to the differences in morphology, particle size, composition and surface functional groups, led to significant effects on the morphology and acidity of the zeolite crystals. These ZSM-5 zeolites exhibited a significantly improved performance in the Methano-To-Olefins (MTO) reaction. Indeed, the catalyst lifetime of parent ZSM-5 started to decline after 6 h, whilst ZSM-5 modified by Grass-C only suffered a loss in conversion after 10 h on stream (at 400 degrees C, WHSV=8 h-1).

In this study, the synthesis of a series of novel glyme-modified ligands and their corresponding copper and zirconium metal-organic frameworks (MOF) has been successfully realized. In addition, while using copper salts, it was possible to yield a water-stable MOF. Besides, the utilization of zirconium salts resulted in the formation of MOF exhibiting a UiO-68 type structure. The thorough characterization of these MOF was performed using Single Crystal X-ray Diffraction (SCXRD), Powder X-ray Diffraction (PXRD), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA) and nitrogen adsorptiondesorption isotherms. Furthermore, the CO2 adsorption capacity of these MOF was also evaluated. Despite the significant differences in their crystalline networks, all MOF exhibited appreciable CO2 adsorption capacities, ranging from 0.6 to 1.3 mmol g- 1 at ambient pressure and 0 degrees C.

The electrocatalytic nitric oxide reduction reaction (NORR) has attracted significant attention as an ecofriendly alternative to the conventional Haber-Bosch process for producing ammonia (NH3). However, the poor selectivity to NH3 and low catalyst stability under harsh conditions are great challenges in NORR. Herein, the core-shell structure of nickel nanoparticles enclosed with a nitrogen-doped carbon layer (Ni@NC) electrocatalyst derived from covalent organic frameworks is employed for high performance in NORR. The Ni@NC-700 achieved the highest FENH3 of 82.94% with an NH3 yield rate of 19.00 mu mol cm(-2) h(-1) at 0.16 V (vs reversible hydrogen electrode) in a 0.1 M HClO4 electrolyte. Control experiments revealed that nickel nanoparticles (Ni NPs) acted as active centers in Ni@NC for efficient production of NH3. The ideal carbon shell protection of Ni NPs and the high inherent catalytic TOF of Ni@NC-700 revealed a promising candidate for an efficient NORR electrocatalyst. The stability test demonstrated the remarkable stability of Ni@NC. The Ni NPs were protected by carbon nanostructures resembling core-shell catalysts, preventing metal dissolution during rough electrolysis.

Adsorption isotherms of pure vapors and vapor mixtures of water, methanol, and cyclohexane were studied using a synthesized 13X zeolite (FAU topology), by means of a DVS gravimetric vapor analyzer. These results were validated by GCMC calculations. The surface chemistry of the adsorbent was characterized by the thermodesorption of ammonia, and its textural properties were studied using nitrogen physisorption. The 13X zeolite was found to be strongly acidic (BrØnsted acid sites, Si/Al = 1.3) and its specific surface area around 1100 m2·g−1. Water was found to be able to diffuse within both the supercages and the sodalite cavities of the FAU structure, whereas methanol and cyclohexane were confined in the supercages only. The water/methanol sorption selectivity of the 13X zeolite was demonstrated by co-adsorption measurements. The composition of the water/methanol adsorbed phase could be calculated by assuming IAST hypotheses. This model failed in the case of the water/cyclohexane co-adsorption system, which is in line with the non-miscibility of the components in the adsorbed state. The sorption isotherms could be successfully simulated, confirming the robustness of the forcefields used. The 13X zeolite confirmed its a priori expected hydrophilic nature, which is useful for the selective adsorption of water in a methanol–water vapor mixture.

Hydrochars synthesized from lignocellulosic waste (rice husk and exhausted black wattle bark) through hydrothermal carbonization were used as pore-forming agents in template-free ZSM-5 zeolites. The influence of the amount of hydrochar added to the zeolite synthesis and the nature of the hydrochar on the zeolite features and catalytic performance were evaluated. It was observed that the hydrochar had little influence on the textural properties and Si/Al ratio of the zeolites. However, the hydrochar was able to enhance the number of Br & oslash;nsted acid sites in the zeolite and led to different ZSM-5 crystal morphologies (french-fries and twinned crystals). The latter zeolites exhibited a higher cracking activity of n-hexane, favoring the formation of light olefins, due to the presence of Br & oslash;nsted sites and suitable shape selectivity. In contrast, they exhibited a lower conversion of methanol into hydrocarbons (MTH), favoring the formation of dimethylether due to rapid deactivation. The hydrochars acted therefore, in the synthesis of template-free ZSM-5 zeolite, as a mean to both raise the acidity and control the aggregation of zeolite crystals.