Total Uptake Capacity Research Articles

Regulating the Hydrophilicity of Hyper-Cross-Linked Polymers via Thermal Oxidation for Atmospheric Water Harvesting.

We explore the thermal oxidation of hyper-cross-linked polymers to enhance their hydrophilicity and efficacy in atmospheric water harvesting. Comprehensive chemical and physical characterizations are used to confirm the successful incorporation of polar oxygen moieties and the preservation of porosity upon thermal treatment. Newly introduced oxygen-based functional groups significantly improve water sorption properties, increasing total water uptake capacities by up to 400% and shifting water uptake onsets to significantly lower relative humidity. We also investigate the regeneration of oxidized hyper-cross-linked polymers after water sorption to probe their potential for multiple water harvesting cycles and reuse. Our findings outline a simple and cost-effective postsynthetic modification route for optimizing porous organic polymers for more sustainable and efficient atmospheric water harvesting.

Carbon dioxide sequestration through mineralization from seawater: The interplay of alkalinity, pH, and dissolved inorganic carbon

Marine carbon dioxide removal technologies rely on the equilibration of seawater with atmospheric CO2, where a pH increase can facilitate CO2 removal either through increased absorption capacity of CO2, or precipitation of minerals. Here, we focus on explicitly defining the governing factors that influence seawater alkalinity with respect to CaCO3 mineralization and atmospheric CO2 uptake. We utilize an electrochemical setup and different water types, such as near-shore Mediterranean seawater and Red Sea Salt water. The setup allows us to separate mineralization from alkalinity enhancement via an electrochemical membrane cell, with a second compartment that allows evaluation of the interplay of ion concentration, precipitation, pH, DIC concentration, and total alkalinity under a controlled evironment. The effect of sparging additional CO2 before, and after the precipitation of CaCO3 was evaluated while utilizing both a mild pH swing (from, ∼8.3 to ∼9.5), and a larger pH swing (from, ∼8.3 to ∼10.2). A thermodynamic model is presented defining the energy consumptionrequired to increase the pH, and the influence of Mg thereon is explicated. Furthermore, we detail theoretical aquatic chemistry simulations via PHREEQC to rationalize the observed intricate dynamics of the carbonate system in seawater. We end with a discussion of the implications of total alkalinity, pH, salt complexation, and carbon uptake capacity relevant to of all ocean alkalinity enhancement and marine-based CO2 removal systems, concluding that the carbon uptake capacity of water returned to the ocean must be verified in such technologies.

Towards low-cost and sustainable activated carbon production: Influence of microwave activation time on yield and CO2 uptake of PET-derived adsorbents

Microwave (MW) heating is proposed as a method to transform polyethylene terephthalate (PET) into porous adsorbents. The yield, textural properties, and CO2 uptake of the PET-derived adsorbents irradiated at different durations (3 – 35 min) at 400 °C were assessed. MW activation time influenced both the physical properties and CO2 uptake capacities of the resulting adsorbents. The yield decreased with activation time, but the surface area, total pore volume, micropore volume, and CO2 uptake capacities all increased with MW activation time before declining. The optimal sample (produced with 5 min of MW activation time) showed improved textural properties as well as higher equilibrium and dynamic CO2 uptakes than the commercial activated carbon used as reference. This adsorbent also possesses good selectivity for CO2 in the binary 10:90%vol/vol CO2: N2 mixture. Additionally, an excellent recyclability over 20 cycles, (Regeneration Efficiency > 97%) was observed, and the CO2 adsorption kinetics best fits Lagergren’s pseudo-second-order model. This study has shown that a low activation temperature (400 °C), a short MW activation time (5 min), and a low amount of chemical agent (KOH, 0.72 M) could produce CO2 adsorbents from a cheap and abundant material (PET-waste) with better CO2 uptake to that of a commercial activated carbon.

Comparing the practical hydrogen storage capacity of porous adsorbents: Activated carbon and metal-organic framework

For the transition to a society powered by hydrogen energy, it is important to ensure the safe delivery of enough hydrogen. One promising method for storing and transporting hydrogen is sorbent-based cryo-adsorption. To assess the effectiveness of this physisorption-based method, hydrogen storage performance can be evaluated in various ways, including (gravimetric and volumetric) excess, absolute, total uptake, and useable capacity. However, previous literature mostly reported one or two of these indicators sporadically, which made it challenging to analyze the practical and comprehensive hydrogen storage capacity. Herein, we evaluate the most practical activated porous carbons and Metal-organic framework (MOF) as hydrogen storage materials using all relevant indicators. Specifically, the optimized useable capacity is defined as the H2 amount per the mass of adsorbent that can be released from the maximum tank pressure to the back pressure at optimized working temperature. This is considered the most practical measure of a tank system's capabilities. Thus, the maximum useable capacity can be determined based on temperature, so it is important to identify the ideal temperature conditions. It is noteworthy that our result revealed opposing the previous stereotypes which claimed that practical hydrogen storage is favored by lower temperatures.

Development of a Mixed Multinuclear Cluster Strategy in Metal-Organic Frameworks for Methane Purification and Storage.

Metal-organic frameworks (MOFs) have attracted extensive attention in methane (CH4) purification and storage. Specially, multinuclear cluster-based MOFs usually have prominent performance because of large cluster size and abundant open metal sites. However, compared to diverse combinations of organic linkers, one MOF with two or more multinuclear clusters is difficult to achieve. In this paper, we demonstrate a mixed multinuclear cluster strategy, which successfully led to three new heterometallic MOFs (SNNU-328-330) with the same common H3TATB [2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine] tritopic linker and six types of multinuclear clusters ([YCd(COO)4(μ2-H2O)], [YCd2(COO)8], [In3(COO)6(μ3-OH)], [In3Eu2(COO)9(μ3-OH)3(μ4-O)], [Y9(COO)12(μ3-OH)14] and [Y2Cd8(COO)16(μ2-H2O)4(μ3-OH)8]). Three MOF adsorbents all show great potentials to remove the impurities (CO2 and C2-hydrocarbons) in natural gas and show prominent high-pressure methane storage capacity. Among them, the ideal adsorbed solution theory separation ratios of equimolar C2H2/CH4, C2H4/CH4, C2H6/CH4, and CO2/CH4 at 298 K for SNNU-328 reach to 29.7-16.0, 19.1-8.2, 33.2-10.3, and 74.3-8.5, which have surpassed many famous MOF adsorbents. Dynamic breakthrough experiments conducted at 273 and 298 K showed that SNNU-330 can separate CH4 from C2H2/CH4, C2H4/CH4, C2H6/CH4, and CO2/CH4 mixtures with the breakthrough interval times of about 48.2, 17.9, 37.2, and 17.1 min g-1 (273 K, 1 bar, v/v = 50/50, 2 mL min-1), respectively. Remarkably, SNNU-329 exhibits extremely high methane storage performance at 298 K with the total uptake and working capacity of 192 cm3 cm-3 (95 bar) and 171 cm3 cm-3 (65 bar) due to the synergistic effects of high surface area, suitable pore sizes, and multiple open metal sites.

Carbon cycle extremes accelerate weakening of the land carbon sink in the late 21st century

Abstract. Increasing surface temperature could lead to enhanced evaporation, reduced soil moisture availability, and more frequent droughts and heat waves. The spatiotemporal co-occurrence of such effects further drives extreme anomalies in vegetation productivity and net land carbon storage. However, the impacts of climate change on extremes in net biospheric production (NBP) over longer time periods are unknown. Using the percentile threshold on the probability distribution curve of NBP anomalies, we computed negative and positive extremes in NBP. Here we show that due to climate warming, about 88 % of global regions will experience a larger magnitude of negative NBP extremes than positive NBP extremes toward the end of 2100, which accelerate the weakening of the land carbon sink. Our analysis indicates the frequency of negative extremes associated with declines in biospheric productivity was larger than positive extremes, especially in the tropics. While the overall impact of warming at high latitudes is expected to increase plant productivity and carbon uptake, high-temperature anomalies increasingly induce negative NBP extremes toward the end of the 21st century. Using regression analysis, we found soil moisture anomalies to be the most dominant individual driver of NBP extremes. The compound effect of hotness, dryness, and fire caused extremes at more than 50 % of the total grid cells. The larger proportion of negative NBP extremes raises a concern about whether the Earth is capable of increasing vegetation production with a growing human population and rising demand for plant material for food, fiber, fuel, and building materials. The increasing proportion of negative NBP extremes highlights the consequences not only of reduction in total carbon uptake capacity but also of conversion of land to a carbon source.

Polymer-encapsulated crystalline zirconium phosphates as NH4+ and K+ ion exchangers for application in sorbent dialysis cartridges

The ion exchange properties of crystalline ⍺- and γ-zirconium phosphates in the sodium and hydrogen forms were investigated. The zirconium phosphates were synthesized by a mechanochemistry-assisted protocol. Amongst the compounds, ⍺-Na2-zirconium phosphate and γ-H2-zirconium phosphate were found to be excellent ion exchangers for NH4+ and K+ ions, two key cations in renal sorbent dialysis systems. The maximum NH4+ uptake by ⍺-Na2-zirconium phosphate was 5.5 mmol/g, close to the theoretical limit of exchangeable sites. In multi-ion solutions, γ-H2-zirconium phosphate was a selective exchanger for K+ with total uptake capacity of 2.9 mmol/g. The as-synthesized microcrystalline zirconium phosphates were encapsulated by polyacrylonitrile to form spherical porous beads of tailorable sizes. Owing to the porosity, access to the ion exchange sites of the embedded zirconium phosphates particles was unaffected, enabling fast kinetics in the uptake of NH4+ and K+. In this form, the PAN/ZrP beads can be easily handled in sorbent cartridges. The activity of the PAN/ZrP beads could be fully restored by simple regeneration with the appropriate electrolyte.

Hydrazine-Hydrazide-Linked Covalent Organic Frameworks for Water Harvesting.

We report a postsynthetic strategy and its implementation to make covalent organic frameworks (COFs) with irreversible hydrazide linkages. This involved the synthesis of three 2D and 3D hydrazine-linked frameworks and their partial oxidation. The linkage synthesis and functional group transformation—hydrazine and hydrazide—were evidenced by 15N multi-CP-MAS NMR. In addition, the isothermal water uptake profiles of these frameworks were studied, leading to the discovery of one hydrazine-hydrazide-linked COF suitable for water harvesting from air in arid conditions. This COF displayed characteristic S-shaped water sorption profiles, a steep pore-filling step below 18% relative humidity at 25 °C, and a total uptake capacity of 0.45 g g–1. We found that even small changes made on the molecular level can lead to major differences in the water isotherm profiles, therefore pointing to the utility of water sorption analysis as a complementary analytical tool to study linkage transformations.

Boosting Ammonia Uptake within Metal–Organic Frameworks by Anion Modulating Strategy

Ammonia with toxic and corrosive features needs advanced protective materials and removal tools, although it is a vital component in human food supply processes. So, to satisfy these requirements, materials with high adsorption capacity and affinity for ammonia should be developed. The present research has been focused on a series zinc-based metal-organic frameworks (MOF) containing mixed ligands, biphenyl dicarboxylic acid (BPDA) and tris(4-(4H-1,2,4-triazol-4-yl)phenyl)amine (TTPA), which are modulated by different anions including CH3COO-, CF3COO-, and CF3SO3-. Ammonia uptake capacity was measured via static and dynamic conditions under 50% relative humidity. Among all compounds, CF3SO3- anion could enhance the ammonia uptake capacity of MOFs up to 177.85 and 349 mg/g during static and breakthrough measurements, respectively, so that 83.30% of the total uptake capacity (at P/Po = 1.0 and 298 K) was achieved at low relative pressure range (up to 0.1). The isosteric heats of ammonia adsorption on PFC-27 and derivatives were calculated in the range of 7.03-10.16 kJ mol-1 so that they increased upon CF3SO3-, CF3COO-, and CH3COO- ion incorporation. This is potentially beneficial for enhanced ammonia adsorption. Interestingly, adsorption capacities were retained with only slight changes after five cycles and three regeneration temperatures, 25 °C, 60 °C, and 120 °C, under vacuum. The special affinity for NH3 adsorption and MOF phase stability after desorption is clearly proved by FTIR spectra and PXRD analysis, respectively. Generally, the results suggest that ion insertion modification is an efficient strategy for enhancement of MOF adsorption performance.

Selective adsorption of CO2 and SF6 on mixed-linker ZIF-7–8s: The effect of linker substitution on uptake capacity and kinetics

A series of mixed-linker Zeolitic Imidazolate Framework(ZIF)-7–8s constructed from different amounts of benzimidazolate (bIm) and 2-methylimidazolate (mIm) linkers were synthesized in this study. We demonstrated that by carefully controlling the ratios between bIm and mIm linkers, the particle morphology and pore size of ZIF-7–8 can be tailored to selectively adsorb CO2 or SF6 with significantly enhanced uptake capacity. ZIF-7–8 with 90% bIm and 10% mIm linkers showed a CO2 uptake of 1.44 mmol g−1 at 293 K (1 bar) and a CO2/N2 selectivity of over 30. On the other hand, ZIF-7–8 with 26% bIm and 74% mIm linkers had a high SF6 uptake of 2.08 mmol g−1 at 293 K (1 bar) as well as a high SF6/N2 selectivity of over 40. Isosteric enthalpy of adsorption calculations and cyclic adsorption experiments confirmed that both CO2 and SF6 were physisorbed on ZIF-7–8. CO2 was found to adsorb rapidly on ZIF-7–8, with over 80% of the total uptake capacity reached within 30 s. Detailed kinetics analysis concluded that the adsorption of CO2 and SF6 on these ZIF-7–8s could be described by pseudo-second order kinetics and the diffusion was found to be governed by a mixture of different mechanisms. The highly tunable sorption properties, high uptake capacity and high selectivity of ZIF-7–8 render them as interesting candidate sorbents for different greenhouse gases.

A Strategy to Revalue a Wood Waste for Simultaneous Cadmium Removal and Wastewater Disinfection

In this investigation, the possibility of wood waste (hardwoods such as oaks’ and alternatives’ staves from Balkan cooperage) revalorization for simultaneous cadmium removal and wastewater disinfection was examined. All samples were characterized in terms of their crystallinity index and crystallite size, amount of functional groups, and surface chemistry (determined by ATR-FTIR) as well as antibacterial activity. Mulberry is characterized by the lowest crystallinity index which can be ascribed to the highest crystallite size disabling crystallite denser packaging, while myrobalan plum has about 23% lower crystallite size that enables crystallite better packaging, thus resulting in a 42.4% higher crystallinity index compared to the mulberry. All oaks have a significantly higher amount of carboxyl groups compared to the alternatives (0.23-0.28 vs. 0.12-0.19 mmol/g). The adsorption experiments revealed that with increasing the initial cadmium concentration from 15 up to 55 mg/g, samples’ adsorption capacity increases by 89-220%. The equilibrium data fit well with the Langmuir isotherm model implying monolayer coverage of cadmium ions over a homogeneous wood surface. The relationship between the samples’ maximum adsorption capacities (ranged from 5.726 to 12.618 mg/g), their crystallinity index, and crystallite size was established. According to ATR-FTIR spectra, aldehyde, carboxyl, hydroxyl, and phenyl groups present on the wood waste surface are involved in Cd2+ adsorption which proceeds via the interplay of the complexation, cation- π interactions, and ion-exchange mechanisms. Mulberry and myrobalan plum showed about 89% and 80% of the total uptake capacity of cadmium within 60 min, while the equilibrium was attained after 240 min of contact time. Good compliance with pseudo-second kinetic order indicated that cadmium adsorption was mediated by chemical forces. Thermodynamic parameters revealed the spontaneous and exothermic character of cadmium ion adsorption onto mulberry and myrobalan plum. All studied samples provide maximum bacterial reduction (>99%) for E. coli and S. aureus. Wood waste from Balkan cooperage can be successfully used for simultaneous cadmium removal and wastewater disinfection.

Waste Jute Fabric as a Biosorbent for Heavy Metal Ions from Aqueous Solution

The influence of the chemical composition on the biosorption potential of waste jute fabric for Ni2+, Cu2+, and Zn2+ was investigated. The raw jute fabric was treated with sodium hydroxide or sodium chlorite to selectively remove hemicelluloses and lignin, respectively. All jute fabrics were characterized by determination of their chemical composition as well as functional group content. The effects of solution pH, contact time, and initial metal ion concentration on the biosorption from monometallic and polymetallic solution by jute fabrics were investigated. The maximum biosorption capacity for all heavy metal ions was observed at pH 5.5. Concerning the contact time, the raw jute fabric shows more than 72 % of the total uptake capacity of Ni2+, Cu2+, and Zn2+ within 1 h, while the jute fabrics with lower hemicelluloses and lignin content show between 72–85 % of the total uptake capacity within 3 h. Increased initial metal ion concentration from 10 to 20 mg/l in monometallic solution caused an increase in the total uptake capacity of jute fabrics with lower hemicelluloses and lignin content for 47–69 % (Ni2+), 42–63 % (Cu2+), and 22–37 % (Zn2+). The biosorption capacity of alkali treated jute fabrics was affected by the changes in the total amount of carboxyl and aldehyde groups that accompany the hemicelluloses removal. In the case of the oxidative treatment, the biosorption capacity was affected by the lignin content as well as the amount of introduced carboxyl groups. The best biosorption performance possesses jute fabric with 63.2 % lower lignin content as well as 81.1 % higher amount of carboxyl groups; biosorption capacity toward Ni2+, Cu2+, and Zn2+ in monometallic solution is about 2.4; 2.2 and 3.5 times higher compared to the raw jute fabric, respectively. All jute fabrics exhibited the same affinity order (which is independent on the initial metal ion concentrations) toward heavy metal ions: Ni2+ > Cu2+ > Zn2+ in the case of competitive biosorption. An increase in the initial metal ion concentration for two times in the polymetallic solution caused about a 35–59 % increase in the total uptake capacity of Ni2+, while the total uptake capacities of Cu2+ and Zn2+ increased for 19–38 % and 18–65 %, respectively.

Methane sorption in a family of qzd-MOFs: A multiscale computational study

A new family of metal-organic frameworks with qzd topology is proposed and exhaustively studied using multiscale computational analysis (grand canonical Monte Carlo; molecular mechanics; density functional theory) to reveal the structure-property relationships for predicting frameworks with high total methane uptake and working capacity. In our approach we take into account different linkers with triple bonds and/or benzene rings. Grand canonical Monte Carlo simulations demonstrate for several of the designed frameworks excellent methane storage properties, such as a balanced working capacity of 56 wt%, 264 cm3 (STP) cm−3 at 5–80 bar and 240 K.

Telescopic synthesis of cellulose nanofibrils with a stable dispersion of Fe(0) nanoparticles for synergistic removal of 5-fluorouracil

The recognition of cellulose nanofibrils (CNF) in the past years as a high prospect material has been prominent, but the impractical cellulose extraction method from biomass remained as a technological barrier for industrial practice. In this study, the telescopic approach on the fractionation of lignin and cellulose was performed by organosolv extraction and catalytic oxidation from oil palm empty fruit bunch fibers. The integration of these techniques managed to synthesize CNF in a short time. Aside from the size, the zeta potential of CNF was measured at −41.9 mV, which allow higher stability of the cellulose in water suspension. The stability of CNF facilitated a better dispersion of Fe(0) nanoparticles with the average diameter size of 52.3–73.24 nm through the formulation of CNF/Fe(0). The total uptake capacity of CNF towards 5-fluorouracil was calculated at 0.123 mg/g. While the synergistic reactions of adsorption-oxidation were significantly improved the removal efficacy three to four times greater even at a high concentration of 5-fluorouracil. Alternatively, the sludge generation after the oxidation reaction was completely managed by the encapsulation of Fe(0) nanoparticles in regenerated cellulose.

Outstanding methane gravimetric working capacity of computationally designed rhr-MOFs

Abstract A multi-scale approach is employed to design metal-organic frameworks (MOFs). The methane sorption properties are studied by grand canonical Monte Carlo simulations to reveal the structure-property relationship with respect to the methane total uptake and working capacity at different temperatures and pressures. We identify rhr-MOFs with outstanding gravimetric working capacity. For example, the BBB MOF (largest studied pore size) achieves a value of 60.7 wt% at 298 K and 5–65 bar.

Understanding Gas Storage in Cuboctahedral Porous Coordination Cages.

Porous molecular solids are promising materials for gas storage and gas separation applications. However, given the relative dearth of structural information concerning these materials, additional studies are vital for further understanding their properties and developing design parameters for their optimization. Here, we examine a series of isostructural cuboctahedral, paddlewheel-based coordination cages, M24(tBu-bdc)24 (M = Cr, Mo, Ru; tBu-bdc2- = 5-tert-butylisophthalate), for high-pressure methane storage. As the decrease in crystallinity upon activation of these porous molecular materials precludes diffraction studies, we turn to a related class of pillared coordination cage-based metal-organic frameworks, M24(Me-bdc)24(dabco)6 (M = Fe, Co; Me-bdc2- = 5-methylisophthalate; dabco = 1,4-diazabicyclo[2.2.2]octane) for neutron diffraction studies. The five porous materials display BET surface areas from 1057-1937 m2/g and total methane uptake capacities of up to 143 cm3(STP)/cm3. Both the porous cages and cage-based frameworks display methane adsorption enthalpies of -15 to -22 kJ/mol. Also supported by molecular modeling, neutron diffraction studies indicate that the triangular windows of the cage are favorable methane adsorption sites with CD4-arene interactions between 3.7 and 4.1 Å. At both low and high loadings, two additional methane adsorption sites on the exterior surface of the cage are apparent for a total of 56 adsorption sites per cage. These results show that M24L24 cages are competent gas storage materials and further adsorption sites may be optimized by judicious ligand functionalization to control extracage pore space.

Dye-Mediated Interactions in Chitosan-Based Polyelectrolyte/Organoclay Hybrids for Enhanced Adsorption of Industrial Dyes.

Noncovalent, dye-mediated interactions between organo-montmorillonites ("organoclays") and a chitosan-based polyelectrolyte are exploited for highly effective and fast removal of different, industrially important anionic dyes (single-azo, double-azo, and anthraquinone) from aqueous solutions. The addition of only 10 wt % of the polyelectrolyte to conventional organoclay results in a 100% increase in absolute dye uptake capacity, an acceleration of dye uptake kinetics by up to 500%, and the flocculation of large, easily separable sorbent aggregates. These substantial improvements in adsorption performance are driven by the mediating effect of the anionic dyes (acting as the electrostatic mediator between the positively charged polyelectrolyte chains and organoclays), enabling the formation of true hybrid sorbent structures without the need for covalent cross-linking chemistry. The dye-mediated sorption and hybrid formation mechanism is further evidenced by structural and chemical characterization of the hybrid sorbents (small-angle X-ray diffraction and IR mapping) as well as by analysis of dye sorption kinetics according to the intraparticle diffusion model. Importantly, the organoclay/polyelectrolyte hybrid system provides a highly interesting adsorbent for the treatment of dye mixtures. Our study shows that structurally different anionic dyes localize at different sites within the hybrid structure (organoclay intergallery spaces vs polyelectrolyte/organoclay interface), enabling the simultaneous adsorption of different dyes with high efficiency. Consequently, the total uptake capacity for dye mixtures was 50% larger than that of individual dyes, demonstrating the enormous potential of the hybrids for industrial wastewater purification, where dye mixtures are ubiquitous.

The Lead [Pb(II)] tolerance and uptake ability of four fungal species, two from the genus Penicillium and two from the genus Talaromyces were investigated in this study. The species were isolated from a polluted tributary and identified to be closest to P. canescens, P. simplicissimum, T. macrosporus and another Talaromyces sp. via PCR targeting their internal transcribed spacer 1 and

The Lead [Pb(II)] tolerance and uptake ability of four fungal species, two from the genus Penicillium and two from the genus Talaromyces were investigated in this study. The species were isolated from a polluted tributary and identified to be closest to P. canescens, P. simplicissimum, T. macrosporus and another Talaromyces sp. via PCR targeting their internal transcribed spacer 1 and 4 sequences. All isolates have tolerances for up to 2000 µg/mL and 3000 µg/mL Pb(II) on solid and liquid medium, respectively. Both Penicillium isolates have increasing removal rates dependent on initial Pb(II) concentration at 500 to 2000 µg/mL, while removal rates of both Talaromyces isolates are not significantly influenced by initial Pb(II) concentrations. The Pb(II) uptake of all isolates increases with increasing Pb(II) concentration but is depressed at 3000 µg/mL, with the exception of T. macrosporus. The recorded total uptake capacities for both Penicillium isolates in this study are higher than in most literature, at 7.0 – 407.4 mg/g and 50.8 – 412.6 mg/g for P. canescens and P. simplicissimum, respectively. The study also reports the exemplary Pb(II) uptake capacities of both Talaromyces isolates at 58.9 – 601.0 mg/g and 60.9 – 402.3 mg/g for T. macrosporus and Talaromyces sp., respectively.

Computational Tuning of the Paddlewheel tcb-MOF Family for Advanced Methane Sorption

A series of metal–organic frameworks (MOFs) with tcb net topology and linkers of increasing size (combining triple bonds and benzene rings) is computationally designed using molecular mechanics and density functional theory. By grand canonical Monte Carlo simulations, we identify MOFs with outstanding methane total uptakes and working capacities, satisfying the targets of the U.S. Department of Energy for automobile applications in cold weather regions (50 wt %, 263 cm3(STP)cm–3). For example, the 5B MOF achieves at 298 K working capacities of 52.2 wt % at 5–65 bar and 61.9 wt % at 5–80 bar. The 3B MOF exhibits at 298 K the most balanced (gravimetric versus volumetric) total uptake and working capacity in the family of tcb-MOFs: 28.4 wt %, 160.9 cm3(STP)cm–3 at 35 bar and 23.0 wt %, 130.3 cm3(STP)cm–3 at 5–35 bar (exceeding the benchmarks of IRMOF-6, PCN-14, Ni-MOF-74, Al-soc-MOF-1, MOF-5, MOF-205), 38.4 wt %, 218.0 cm3(STP)cm–3 at 65 bar and 33.0 wt %, 187.5 cm3(STP)cm–3 at 5–65 bar (exceeding the benchm...

Reactive Uptake of Sulfur Dioxide and Ozone on Volcanic Glass and Ash at Ambient Temperature

AbstractThe atmospheric impacts of volcanic ash from explosive eruptions are rarely considered alongside those of volcanogenic gases/aerosols. While airborne particles provide solid surfaces for chemical reactions with trace gases in the atmosphere, the reactivity of airborne ash has seldom been investigated. Here we determine the total uptake capacity (NiM) and initial uptake coefficient (γM) for sulfur dioxide (SO2) and ozone (O3) on a compositional array of volcanic ash and glass powders at ~25°C in a Knudsen flow reactor. The measured ranges of NiSO2 and γSO2 (1011–1013 molecules cm−2 and 10−3–10−2) and NiO3 and γO3 (1012–1013 molecules cm−2 and 10−3–10−2) are comparable to values reported for mineral dust. Differences in ash and glass reactivity toward SO2 and O3 may relate to varying abundances of, respectively, basic and reducing sites on these materials. The typically lower SO2 and O3 uptake on ash compared to glass likely results from prior exposure of ash surfaces to acidic and oxidizing conditions within the volcanic eruption plume/cloud. While sequential uptake experiments overall suggest that these gases do not compete for reactive surface sites, SO2 uptake forming adsorbed S(IV) species may enhance the capacity for subsequent O3 uptake via redox reaction forming adsorbed S(VI) species. Our findings imply that ash emissions may represent a hitherto neglected sink for atmospheric SO2 and O3.