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Herein, a robust microporous aluminum tetracarboxylate framework, MIL‐120(Al)‐AP, (MIL, AP: Institute Lavoisier and Ambient Pressure synthesis, respectively) is reported, which exhibits high CO2 uptake (1.9 mmol g−1 at 0.1 bar, 298 K). In situ Synchrotron X‐ray diffraction measurements together with Monte Carlo simulations reveal that this structure offers a favorable CO2 capture configuration with the pores being decorated with a high density of µ2‐OH groups and accessible aromatic rings. Meanwhile, based on calculations and experimental evidence, moderate host‐guest interactions Qst (CO2) value of MIL‐120(Al)‐AP (−40 kJ mol−1) is deduced, suggesting a relatively low energy penalty for full regeneration. Moreover, an environmentally friendly ambient pressure green route, relying on inexpensive raw materials, is developed to prepare MIL‐120(Al)‐AP at the kilogram scale with a high yield while the Metal‐ Organic Framework (MOF) is further shaped with inorganic binders as millimeter‐sized mechanically stable beads. First evidences of its efficient CO2/N2 separation ability are validated by breakthrough experiments while operando IR experiments indicate a kinetically favorable CO2 adsorption over water. Finally, a techno‐economic analysis gives an estimated production cost of ≈ 13 $ kg−1, significantly lower than for other benchmark MOFs. These advancements make MIL‐120(Al)‐AP an excellent candidate as an adsorbent for industrial‐scale CO2 capture processes. [ABSTRACT FROM AUTHOR]

Fouling is one of the barriers to developing more efficient and near-zero emission internal combustion engines. The micron-sized particulate matter is one of the roots of this fouling phenomenon in exhaust gas recirculation (EGR) coolers. This fouling is inadequately evaluated quantitatively, and its deposition mechanism is unknown. To investigate the effect of gravity on the deposition of micron-sized particles, an original nondestructive sampling fouling method and experiment apparatus have been developed to effectively obtain the upper and lower bottom fouling in the cooler in the direction of airflow, and the area proportion, count, and diameter of large particles in the fouling using image processing software. It was found that (i) the area proportion of large particles in the lower bottom fouling was almost 2.5 times higher than the upper bottom fouling; (ii) the count of large particles in the lower bottom fouling was higher, and the maximum diameter was larger, up to 639mm; (iii) the mass of the lower bottom fouling was 1.5 times higher than the upper bottom fouling; (iv) gravity can significantly promote the deposition of micron-sized particles and should be considered in the design and arrangement of the EGR cooler to prevent fouling. [ABSTRACT FROM AUTHOR]

Iron(III) carboxylate based metal organic frameworks (MOFs)/porous coordination polymers (PCPs) have sparked great interest owing to their high structural diversity and tunable porosity, excellent stability, tailored functionality and their scalability as well as green synthesis associated with their biocompatible and biodegradable character. Herein, we present a new robust Fe(III) based PCP (labelled MIL-178(Fe)) built up from chains of corner sharing Fe octahedra interconnected by 1,2,4-benzene tricarboxylic acid, delimiting one dimensional narrow pore channels (pore diameter < 4.5 Å) decorated with polar groups (μ2-OH and --CO2H functions). These structural and chemical features are suitable for the selective adsorption of CO2. MIL-178(Fe) was synthesized following a simple and green protocol in water under near ambient conditions using non-toxic reactants, allowing the production of sub-micrometer sized MIL-178(Fe) particles in a large amount (30 g). As shown by single-gas isotherms and CO2/N2 co-adsorption experiments as well as molecular simulations, this material exhibits a moderate CO2 capacity at low pressure but a high CO2/N2 selectivity. This is fully consistent with the presence of μ2-OH groups acting as CO2 adsorption sites, as revealed from both molecular simulations and in situ PXRD experiments. Finally, the good compatibility of this MOF with the elastomer block copolymer Pebax®-3533 allowed the processing of homogeneous and defect-free mixed matrix membranes with a MIL-178(Fe) loading of up to 25 wt% that outperformed pure Pebax®-3533 membranes for CO2/N2 separation. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs)/graphene oxide (GO) composites are of growing interest due to their properties which can exceed those of the pure components, including post-combustion CO2 capture. Series of composites suitable for CO2 capture under flue gas conditions based on the microporous water stable MIL-91(Ti) have been prepared with different GO contents, following two routes, in situ and post-synthetic. It was observed that the 5 wt% GO in situ composite exhibits a semi-conducting behavior, while the post-synthetic materials are insulating, even with high (20 wt%) GO content. As a consequence, this composite absorbs microwave radiation more efficiently compared to the pure MOF and post-synthetic materials. Finally, we report that CO2 desorption is much faster under microwave irradiation compared to direct electric heating on MOF/GO in situ materials, paving the way for future energy-saving microwave swing adsorption processes. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) are one of the main contributors to air pollution. To reduce anthropogenic emissions, it is necessary to improve existing techniques such as catalytic oxidation through the development of new cost‐effective catalysts. Although many studies deal with the development and testing of new materials, most are performed at laboratory scale, of which only a few study mixtures of VOCs. To assess their viability for industrial applications, further tests are required, namely, mixture tests at intermediate scale in relevant environment and extrapolated on an industrial scale. In this work, the catalytic performance of a new mixed oxide Co‐Al‐Ce was investigated towards the oxidation of the n‐butanol and toluene on a semi‐pilot scale (TRL 4). Single component and mixture experiments were performed for several concentrations at a fixed flow rate. A commercial catalyst Pd/γ‐Al2O3 was used as the benchmark to evaluate the performance of the mixed oxide. The Co‐Al‐Ce catalyst enables complete oxidation of n‐butanol at the same temperature as the reference catalyst. Moreover, it provides a better selectivity for n‐butanol, while providing an equivalent one for the oxidation of toluene. In mixtures, the presence of n‐butanol promotes the oxidation of toluene for both catalysts but more significantly for the Co‐Al‐Ce catalyst. The presence of toluene inhibits the oxidation of n‐butanol for the Co‐Al‐Ce and promotes it for high conversions of n‐butanol for the Pd/γ‐Al2O3 catalyst. [ABSTRACT FROM AUTHOR]

Carbon dioxide utilization is increasingly attracting interest. CO2 utilization involves a multitude of processes and chemical reactions. In this context, the goal of this review is to analyze the techno‐economic feasibility, sustainability, and social opportunities of CO2 utilization, as a possible contribution to CO2 mitigation in Europe. Industries and the most recent European projects related to carbon capture and utilization are also discussed, illustrating Europe's performance dynamics in science, research, and innovation in this field. The latest developments in CO2 utilization are thus reviewed, including chemicals, mineral carbonation, and biological uses. This study examines a few CO2‐based pathways at high level of maturity covering a wide range of applications, and discusses their current technical feasibility, economic viability, sustainability, and social aspects. They are then evaluated using several indicators to provide a figure of merit, where qualitative results are intended. The mapping and ranking of CO2 utilization pathways may provide a valuable means in prioritizing support and funding to facilitate the development of large‐scale CO2 utilization projects in Europe. Finally, key challenges and opportunities are discussed. The review shows that CO2 utilization may not be a complete solution for Europe, but will support climate change objectives, circular economy, and resource and energy security. [ABSTRACT FROM AUTHOR]

Different techniques to prepare activated carbons exist. Most of them lead to materials with interesting properties, however, as far as we know, these features have been barely evaluated over time. In this context, the evolution of the textural and surface chemistry properties over time of different activated carbons is evaluated. For this purpose, six commercial and a homemade synthetized activated carbons with different characteristics were put in a climatic chamber for 22 months under constant conditions of temperature and relative humidity (T = 40 °C, RH = 80%). The samples were characterized at different periods of time by means of N2, CO2 and H2O adsorption measurements and by thermogravimetric analysis. The results show that contrary to what can be expected, the surface chemistry was not the only property that has undergone modifications but also the porous properties, and for some samples the latter was even very important. These changes were observed for all samples; however some of them are more affected like metal impregnated carbon and activated carbon fibers, whereas others seem to be more resistant to ageing such as chemically activated carbons. [ABSTRACT FROM AUTHOR]

Catalytic total oxidation is an effective technique for the treatment of industrial VOCs principally resulting from industrial processes using solvents, and usually containing mono-aromatics (BTEX) and oxygenated compounds (acetone, ethanol, butanone). The catalytic total oxidation of VOCs on noble metal materials is effective. However, the cost of catalysts is a main obstacle for the industrial application of these VOC removal processes. Therefore, the aim of this work is to propose an alternative material to palladium-based catalysts (which are suitable for VOCs' total oxidation): a mixed oxide synthesized in the hydrotalcite way, namely CoAlCeO. This material was compared to four catalytic materials containing palladium, selected according to the literature: Pd/α-Al2O3, Pd/HY, Pd/CeO2 and Pd/γAl2O3. These materials have been studied for the total oxidation of toluene, butanone, and VOCs mixtures. Catalysts' performances were compared, taking into account the oxidation byproducts emitted from the process. This work highlight that the CoAlCeO catalyst presents better efficiency than Pd-based materials for the total oxidation of a VOCs mixture. [ABSTRACT FROM AUTHOR]

Porous materials are recognized as very promising materials for water-sorption-based energy storage and transformation. This study presents the first attempt to use Metal Organic Frameworks (MOFs) as host matrices of salts for the preparation of composite sorbents for seasonal heat storage. We have considered six water stable MOFs (i.e. MIL-127(Fe), MIL-100(Fe), MIL-101(Cr), UiO-66(Zr)–NH2, MIL-125(Ti)–NH2 and MIL-160(Al)) differing in their crystalline structure, hydrophilic–hydrophobic balance, pore size/shape and pore volume. The successful encapsulation of CaCl2 in the pores of MOFs leads to two series of MOFs–CaCl2 composites whose salt content could be finely tuned depending on the pore volume of MOFs and the synthesis conditions. These materials were fully characterized by combining multiple techniques (i.e. powder X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, X-ray energy-dispersive spectrometry elemental mapping, N2 sorption and elemental analysis). The water sorption properties of these composites were studied under conditions of a solar heat storage system (i.e. adsorption at 30 °C, desorption at 80 °C, both steps at a water vapour pressure of 12.5 mbar) in comparison to the parent MOFs. We analyze how the physico-chemical and structural properties of these host matrices impact the energy density of composite sorbents. We show that two mesoporous MOFs–CaCl2 composites (i.e. MIL-100(Fe)/CaCl2 and MIL-101(Cr)/CaCl2) with the highest salt loading (46 and 62 wt% respectively) exhibit very high energy storage capacities (up to 310 kW h m−3 (485 W h kg−1)) outperforming the best composites or physical sorbents reported so far together with very little loss upon adsorption–desorption cycling and high chemical stability upon ageing (up to 18 months). [ABSTRACT FROM AUTHOR]

The energy-storage capacities of a series of water-stable porous metal-organic frameworks, based on high-valence metal cations (Al3+, Fe3+, Cr3+, Ti4+, Zr4+) and polycarboxylate linkers, were evaluated under the typical conditions of seasonal energy-storage devices. The results showed that the microporous hydrophilic Al-dicarboxylate MIL-160(Al) exhibited one of the best performances. To assess the properties of this material for space-heating applications on a laboratory pilot scale with an open reactor, a new synthetic route involving safer, greener conditions was developed. This led to the production of MIL-160(Al) on a 400 g scale, before the material was shaped into pellets through a wet-granulation method. The material exhibited a very high energy-storage capacity for a physical-sorption material (343 Wh kg−1), which is in full agreement with the predicted value. [ABSTRACT FROM AUTHOR]

A cooperative experimental/modeling strategy was used to unveil the structure/gas separation performance relationship for a series of isostructural metal–organic frameworks (MOFs) with soc-topology (square-octahedral) hosting different extra-framework counter ions (NO3−, Cl− and Br−). In3+-, Fe3+-, Ga3+- and the newly isolated Al(iii)-based isostructural soc-MOF were extensively studied and evaluated for the separation-based production of high-quality fuels (i.e., CH4, C3H8 and n-C4H10) and olefins. The structural/chemical fine-tuning of the soc-MOF platform promoted equilibrium-based selectivity toward C2+ (C2H6, C2H4, C3H6 C3H8 and n-C4H10) and conferred the desired chemical stability toward H2S. The noted dual chemical stability and gas/vapor selectivity, which have rarely been reported for equilibrium-based separation agents, are essential for the production of high-purity H2, CH4 and C2+ fractions in high yields. Interestingly, the evaluated soc-MOF analogues exhibited high selectivity for C2H4, C3H6 and n-C4H10. In particular, the Fe, Ga and Al analogues presented relatively enhanced C2+/CH4 adsorption selectivities. Notably, the Ga and Al analogues were found to be technically preferable because their structural integrities and separation performances were maintained upon exposure to H2S, indicating that these materials are highly tolerant to H2S. Therefore, the Ga-soc-MOF was further examined for the selective adsorption of H2S in the presence of CO2- and CH4-containing streams, such as refinery-off gases (ROG) and natural gas (NG). Grand canonical Monte Carlo (GCMC) simulations based on a specific force field describing the interactions between the guest molecules and the Ga sites supported and confirmed the considerably higher affinity of the Ga-soc-MOF for C2+ (as exemplified by n-C4H10) than for CH4. The careful selection of an appropriate metal for the trinuclear inorganic molecular building block (MBB), i.e., a Ga metal center, imbues the soc-MOF platform with the requisite hydrolytic stability, H2S stability, and exceptional gas selectivity for ROG and NG upgrading. Finally, the soc-MOF was deployed as a continuous film on a porous support, and its gas permeation properties as a membrane were evaluated. [ABSTRACT FROM AUTHOR]

A multidisciplinary approach combining advanced experimental and modelling tools was undertaken to characterize the promises of a small-pore type Ti-based metal–organic framework, MIL-91(Ti) for CO2 capture. This material was prepared using two synthesis strategies, i.e. under hydrothermal conditions and under reflux, and its single component adsorption behaviour with respect to CO2, CH4 and N2 was first revealed by gravimetry measurements. This hydrophilic and highly water stable MOF is characterized by a relatively high CO2 adsorption enthalpy. Molecular simulations combined with in situ powder X-ray diffraction evidenced that this is due to the combined interaction of this probe with N–H and P–O groups in the phosphonate linker. High CO2 selectivities in the presence of either N2 or CH4 were also predicted and confirmed by co-adsorption measurements. The possibility to prepare this sample under reflux represents an environmentally friendly route which can easily be upscaled. This green synthesis route, excellent water stability, high selectivities and relatively fast transport kinetics of CO2 are significant points rendering this sample of utmost interest for CO2 capture. [ABSTRACT FROM AUTHOR]

The article discusses research on a water stable metal-organic framework with optimal features for carbon dioxide (CO2) capture. It mentions the reduction of anthropogenic CO2 emission from post-combustion flue gas to minimize its effect on the environment. It also offers information on ideal adsorbed solution theory (IAST).

The article discusses a study which demonstrated that a new Zr-based metal-organic framework (MOF), containing two carboxylic functions grafted on the organic linkers, which shows great promises for carbon dioxide-nitrogen gas mixture separation with good selectivity and relatively high working capacity. This material can be used as an alternative to conventional porous solids involved in the physiorption-based processes.

Hybrid porous solids, with their tunable structures, their multifunctional properties and their numerous applications, are currently topical, particularly in the domain of adsorption and storage of greenhouse gases. Most of the data reported so far concern the performances of these solids in this domain, particularly in terms of adsorbed amounts of gas but do not explain at the atomic level why and how adsorption and storage occur. From a combination of structural, spectroscopic, thermodynamic experiments and of molecular simulations, this tutorial review proposes answers to these open questions with a special emphasis on CO2 and CH4storage by some rigid and flexible hybrid porous materials. [ABSTRACT FROM AUTHOR]

Hybrid porous solids, with their tunable structures, their multifunctional properties and their numerous applications, are currently topical, particularly in the domain of adsorption and storage of greenhouse gases. Most of the data reported so far concern the performances of these solids in this domain, particularly in terms of adsorbed amounts of gas but do not explain at the atomic level why and how adsorption and storage occur. From a combination of structural, spectroscopic, thermodynamic experiments and of molecular simulations, this tutorial reviewproposes answers to these open questions with a special emphasis on CO2and CH4storage by some rigid and flexible hybrid porous materials. [ABSTRACT FROM AUTHOR]

In this paper we present adsorption isotherms of carbon dioxide on five different activated carbons from CHEMVIRON CARBON Belgium (Centaur HSV, BPL 410, F30-470, WS 42, Reactivated) and on a carbon molecular sieve from BERGBAU FORSCHUNG Gmbh (CMS II). The temperature is 303 K and the pressure ranges from 100 kPa up to 4000 kPa. Such conditions correspond to relative pressures ranging from 0.01 to 0.5. We also provide, for the same six sorbents, the nitrogen isotherms at 77 K (pressure: 0.001 to 100 kPa, relative pressure: 10-5 to 1). A theoretical treatment based on the Dubinin-Radushkevich and Stoeckli concept is presented and applied to the experimental results in order to obtain the micropore size distribution function (considered as Gaussian) of each sorbent. Using the CO2 data, it is possible to point out important structural differences between the six carbons. The theoretical treatment provides micropore size distribution functions in agreement with what is physically expected. Using N2 data, the structural differences are not so well marked. As a consequence, the structural parameters provided by the theoretical treatment are not reliable: except for the total micropore volume, they fluctuate strongly when changing the relative pressure domain of the used data. [ABSTRACT FROM AUTHOR]

A combination of adsorption, microcalorimetry, infra-red spectroscopy and modeling has been implemented to reveal the potential of the H2S resistant amino-functionalized Ti MOF MIL-125 porous solid for the concomitant elimination of CO2 and H2S from biogas and natural gas. [ABSTRACT FROM AUTHOR]

Contaminated methanol has very good potential for being utilized in formaldehyde production instead of its destructive abatement. The activities, selectivities and stabilities of cobalt–alumina and cobalt–alumina–ceria catalysts prepared by the hydrotalcite-method were investigated in formaldehyde production from emissions of methanol and methanethiol. Catalysts were thoroughly characterized and the relationships between the characterization results and the catalytic performances were drawn. The preparation method used led to the formation of spinel-type structures in the form of Co2AlO4 based on x-ray diffraction (XRD) and Raman spectroscopy. Ceria seems to be present as CeO2, even though interaction with alumina is possible in the fresh catalyst. The same structure is maintained after pelletizing the cobalt–alumina–ceria catalyst. The cobalt–alumina–ceria catalyst was slightly better in formaldehyde production, probably due to lower redox temperatures and higher amounts of acidity and basicity. Methanol conversion is negatively affected by the presence of methanethiol; however, formaldehyde yields are improved. The stability of the pelletized catalyst was promising based on a 16 h experiment. During the experiment, cobalt was oxidized (Co2+ → Co3+), cerium was reduced (Ce4+ → Ce3+) and sulfates were formed, especially on the outer surface of the pellet. These changes affected the low temperature performance of the catalyst; however, the formaldehyde yield was unchanged. [ABSTRACT FROM AUTHOR]