High Mesopore Volume Research Articles

Synthesis and consequence of three-dimensionally ordered macroporous Beta zeolite supported NiW catalyst for efficient hydrocracking of 1-methylnaphthalene to BTX

The three-dimensionally ordered macroporous Beta (3DOM-Beta) zeolite was prepared and used as support of NiW sulfide catalyst for hydrocracking. The as-prepared NiW/3DOM-Beta catalyst possessed a high specific surface area and external specific surface area up to 499 m2/g and 241 m2/g, respectively, and a small average layer length (3.62 nm), a high highest average stacking number (4.64) and dispersion (fW=0.24) of metal sulfide phase, which are characteristic of high hydrogenation activity. Its high mesopore volume (0.25 cm3/g) and the highly ordered interconnected macro-meso-microporosity hierarchical structure significantly facilitated diffusive mass transfer. Compared to the NiW sulfide supported on conventional Beta (C-Beta), alkali-treated Beta (A-Beta) and nanosized Beta (Nano-Beta) zeolites, NiW/3DOM-Beta catalyst showed the highest BTX selectivity and yield of 40.7 % and 40.2 % (33.2 % and 32.6 % on NiW/C-Beta, 34.8 % and 33.9 % on NiW/A-Beta, 37.2 % and 36.6 % on NiW/Nano-Beta), and the highest hydrocracking activity (TOF=2.11 × 10-2∙s−1) as well as the smallest coking content (6.7 wt%). This work not only reveals the promotion effects of the ordered mesopore structure of supports on metal dispersion, accessibility of acid sites, diffusion of reactants and products for designing hydrocracking catalyst, but also shows the potential practical application of 3DOM zeolites with interconnected macro-meso-microporosity for the efficient catalytic conversion of macro-hydrocarbons via hydroupgrading.

Simple and sustainable synthesis of loosely stacked nano-H-ZSM-5 aggregates from kaolin and catalytic studies

The conversion of natural clay to crystalline zeolites has been the subject of considerable interest from both academic and industrial circles. We present an effective strategy for converting kaolin to ZSM-5 zeolite, addressing the issue of reduced mesopore formation in conventional nano-ZSM-5 aggregates due to close-packing. This strategy utilizes kaolin as the sole source of silicon and aluminum, and by decoupling the nucleation and growth of ZSM-5 crystals, loosely stacked nano-H-ZSM-5 aggregates with high crystallinity crystals can be synthesized in a solid-like system by employing a tiny amount of TPAOH (TPAOH/SiO2 = 0.064). The resulting nano-H-ZSM-5 aggregates exhibited high specific surface area (405.66 m2/g), high mesopore volume (0.64 cm3/g), and superior catalytic activity. This strategy offers a novel approach to the cost-effective synthesis of nano-H-ZSM-5 aggregates suitable for industrial applications.

The Utilization of Rice Husk as Both the Silicon Source and Mesoporous Template for the Green Preparation of Mesoporous TiO2/SiO2 and Its Excellent Catalytic Performance in Oxidative Desulfurization.

In recent years, TiO2-based catalysts have received extensive attention from researchers for their excellent oxidative desulfurization (ODS) performances. In this paper, a series of mesoporous TiO2/SiO2 catalysts with different TiO2 loadings are prepared, using an incipient wetness impregnation method with agricultural waste rice husk as both the silicon source and mesoporous template and tetrabutyl titanate as the titanium source. The effect of different TiO2 loadings on the ODS performance of the samples is investigated, and the appropriate TiO2 loading is 2.5%. Compared with pure TiO2, the 2.5%TiO2/SiO2 sample exhibits high catalytic activity for oxidative desulfurization. This is, on the one hand, due to the high specific surface area and mesopore volume of the 2.5%TiO2/SiO2 sample. On the other hand, it is due to the uniform dispersion of TiO2 grains with an average diameter of 6.1 nm on the surface of the mesoporous SiO2 carrier, which greatly increases the active sites of the 2.5%TiO2/SiO2 sample, thus improving the catalytic activity of the sample. The recycling performances of the 2.5%TiO2/SiO2 sample are further investigated. The results show that, after fifteen cycles, the 2.5%TiO2/SiO2 sample still maintains high conversions of dibenzothiophene (99.8%) and 4,6-dimethyldibenzothiophene (99.7%) without deactivation. In addition, the 2.5%TiO2/SiO2 sample treated with TBHP aqueous solution is characterized by the technique of UV-Vis, and the Ti-peroxo (Ti-OOtBu) species, the active intermediate for the ODS of bulky organic sulfides, is successfully captured. Finally, a possible reaction mechanism for the ODS process over the 2.5%TiO2/SiO2 sample is proposed.

Fe3C@C composite fiber mats prepared by electrospinning with heat treatment and their application to Li-S batteries

The main challenges facing Li-S batteries stem from the low conductivity of sulfur and the dissolution of lithium polysulfides. This study addresses these issues by synthesizing Fe3C@C nanofibers through electrospinning followed by heat treatments, which are then applied as an interlayer in Li-S cells. The pre-oxidation temperature is adjusted to achieve the desired material properties, in which Fe3C nanoparticles are embedded in graphitic carbon nanofibers, resulting in a high specific surface area and mesopore volume. This configuration provides excellent polysulfide adsorption and catalytic properties for their further conversion. Consequently, when used as an interlayer, the electrochemical performance of the cell, including discharge capacity (first: 1174 vs. 850 mAh g−1 at 0.1 C), stability (852 vs. 400 mAh g−1 after 100 cycles), and rate-capability (620 vs. 100 mAh g−1 at 2 C), is significantly enhanced compared to cells without interlayer.

Removal of Bisphenol S (BPS) by Adsorption on Activated Carbons Commercialized in Brazil.

This study assessed three powdered activated carbons (BETM, COCO, and SIAL) commercialized in Brazil at the bench scale in agitated reactors, analyzing their kinetic behavior and adsorptive capacity for BPS and BPA in ultrapure water. BETM exhibited the highest adsorption capacities (Q0max) for BPS and BPA at 260.62 and 264.64 mg/g, respectively, followed by SIAL, with a Q0max of 248.25 mg/g for BPS and for 231.20 mg/g BPA, and COCO, with a Q0max of 136.51 mg/g for BPS and 150.03 mg/g for BPA. The Langmuir isotherm model can describe the processes well. A pseudo-second-order model can describe the adsorption kinetics, and SIAL carbon had the highest rate constants (7.45 × 10-3 mg/g/min for BPS and 2.84 × 10-3 mg/g/min for BPA). The Weber-Morris intraparticle diffusion model suggests intraparticle diffusion as the rate-limiting step of all adsorption processes. Boyd's model confirmed more than the mechanism actuating in the bisphenol adsorption. The results suggest that adsorbents with basic surfaces, high specific surface areas, and high mesopore volumes tend to remove BPS and BPA efficiently. Therefore, activated carbons can effectively complement the existing treatment in Brazilian water treatment plants (WTPs).

Excellent adsorption and catalytic oxidation of toluene facilitated by metal-free nitrogen-doped mesoporous biochar

In this study, we synthesized a series of nitrogen-doped mesoporous biochar by a salt-templating method to assess the potential of our modified biochar for advanced remediation of toluene through either adsorption or catalytic oxidation. The principal findings indicated that the incorporation of nitrogen and the mesopore-forming agent significantly influenced the toluene removal performance by altering the physicochemical properties of the biochar. Notably, the sample synthesized at 900 °C (BUPZ-900) exhibited the exceptional toluene adsorption capacity, reaching 283.85 mg/g, due to its high surface area and mesopore volume. Advanced characterizations revealed that different nitrogen functionalities played distinct roles in the adsorption performance. The presence of graphitic nitrogen in BUPZ-900 enhanced toluene adsorption through π-π dispersion interactions. Conversely, BUPZ-600, boasting a high nitrogen content (8.66 at%) and a predominance of pyridinic-N (3.92 at%), exhibited the highest catalytic activity, despite its low adsorption capacity attributed to a smaller surface area. This heightened activity was attributed to the basicity of pyridinic-N, which acted as active sites, despite the material’s lower surface area. Our study highlights the promise of nitrogen-doped mesoporous biochar as an effective adsorbent or catalyst for advanced remediation of volatile organic compounds (VOCs), even in the absence of metal catalysts. This work emphasizes the critical role of synthesis temperature and nitrogen functionalization in optimizing biochar properties for environmental applications.

Coupling physiochemical adsorption with biodegradation for enhanced removal of microcystin-LR in water

To innovate the design of water treatment technology for algal toxin removal, this research investigated the mechanisms of cyanotoxin microcystin-LR (MC-LR) removal by a coupled adsorption-biodegradation. Eight types of woody carbonaceous adsorbents with and without Sphingopyxis sp. m6, a MC-LR degrading bacterium, were tested for MC-LR removal in water. All adsorbents showed good adsorption capability, removing 40 % to almost 100 % of the MC-LR (4.5 mg/L) within 48 h in batch experiments. Adding Sphingopyxis sp. m6 continuously promoted MC-LR biological removal, and successfully broke the barrier of adsorption capacity of tested adsorbents, removing >90 % of the MC-LR in most of the coupled adsorption-biodegradation tests, especially for those adsorbents had low physiochemical adsorption capacity. Variance partitioning analysis indicated that mesopore was the dominant contributor to adsorption capacity of MC-LR in pure adsorption treatments, which acted synergistically with electrical conductivity, polarity and total functional groups on the absorbent. Pore structure was the key factor beneficial for the growth of Sphingopyxis sp. m6 (51% contribution) and subsequent MC-LR biological removal rate (80 % contribution). Overall, pinewood-based carbonaceous adsorbents (especially pinewood activated carbon) exhibited the highest adsorption capacity towards MC-LR and provided the most favorable conditions for biological removal of MC-LR, largely because of their high mesopore volume, total functional groups and electric conductivity. The research outcomes not only deepened the quantitative understanding of mechanisms for MC-LR removal by the coupled process, but also provided theoretical basis for future materials' selection and modification during the practical application of coupled process.

Green and stable synthesis of MCM-56 zeolite by using choline chloride as template

It is desirable to develop eco-friendly structure-directing agents as an alternative to the highly toxic templates during the synthesis process of many zeolites. In this work, a MWW type zeolite (denoted as CC-MCM-56) was stably synthesized with ITQ-1 seed assistance by using a green and nuisance-less choline chloride (CC) as organic structure-directing agents instead of the conventional toxic (HMI) template. The CC-MCM-56 zeolite exhibited similar physicochemical properties to the conventional MCM-56 (HMI), including acid properties, high specific surface area, especially high external specific surface area and mesoporous volume, which performed an excellent result in the liquid-phase alkylation reaction of benzene with long-chain olefins. Our findings reveal that the synergistic effect of ITQ-1 seed and CC molecule enable a longer and more stable crystallization period during the synthesis process of MCM-56 zeolite. The SAXS result coupled with other techniques indicate that ITQ-1 seed is firstly dissolved to form more structural units which could interact with CC molecules, making more CC molecules attached to the surface half cup of the MWW lamellae and promoting the stable synthesis of CC-MCM-56 zeolite with thinner-layer structure. Finally, the synthesized CC-MCM-56 zeolite showed high reactivity and the conversion of 1-hexane and 1-dodecene achieved 90.5% and 90.6% respectively.

Application of Artificial Neural Network (ANN) as a predictive tool for the removal of pharmaceutical from wastewater streams using biochar: a multifunctional technology for environment sustainability

This study investigates biochar as an attractive option for removing pharmaceuticals from wastewater streams utilizing data from various literature sources and also explores the sensitivity of the characteristics and implementation of biochar. ANN 1 was designed to determine the optimal biochar characteristics (Surface Area, Pore Volume) to achieve the maximum percentage removal of pharmaceuticals in wastewater streams. ANN 2 was developed to identify the optimal biomass feedstock composition, pyrolysis conditions (temperature and time), and chemical activation (acid or base) to produce the optimal biochar from ANN 1. ANN 3 was developed to investigate the effectiveness of the biochar produced in ANN 1 and 2 in removing dye from water. Biomass feedstock with a high lignin content and high volatile matter at a high pyrolysis temperature, whether using an acid or base, achieves a high mesopore volume and high surface area. The biochar with the highest surface area and mesopore volume achieved the highest removal percentage. Regardless of hydrophobicity conditions, at low dosages (0.2), a high surface area and pore volume are required for a high percent removal. And with a higher dosage, a lower surface area and pore volume is necessary to achieve a high percent removal.

Porous carbonaceous materials simultaneously dispersing N, Fe and Co as bifunctional catalysts for the ORR and OER: electrochemical performance in a prototype of a Zn-air battery.

Infiltration of the mesoporous structure of SBA-15 silica as a hard template with phenanthroline complexes of Fe3+ and Co2+ allowed the simultaneous dispersion of nitrogen, iron and cobalt species on the surface of the obtained carbonaceous CMK-3 silica replica, with potential as bifunctional heterogeneous catalysts for the cathodic oxygen reduction and evolution reactions (ORR and OER). The textural properties and mesopore structure depended on the composition of the material. The carbonaceous FeCoNCMK-3 (1/1), obtained with an Fe/Co molar ratio of 1/1, exhibited an ordered cylindrical mesoporous structure with a high mesopore volume, a rather homogeneous composition in terms of total and surface concentrations of iron and cobalt, and a balanced presence of pyridinic-, pyrrolic- and graphitic-N species. FeCoNCMK-3 (1/1) could improve the ORR kinetics by adsorption and reduction of O2 through the 4-electron mechanism with a current density of -17.37 mA cm-2, Eonset of 1.13 V vs. RHE and E1/2 of 0.75 V when compared to metal-free, monometallic or bimetallic electrocatalysts with a higher amount of cobalt than that of iron. In addition, FeCoNCMK-3 (1/1) exhibited activity for the OER, presenting lower values of Eonset (1.52 V), Ej10 (1.78 V) and the Tafel slope (76.3 mV dec-1) with respect to other catalysts. When evaluated as a cathode in a prototype of a Zn-air battery, FeCoNCMK-3 (1/1) exhibited a high open circuit voltage of 1.41 V, a peak power density of 66.84 mW cm-2, a large specific capacity of 818.88 mA h gZn-1, and cycling for 20 h but with deactivation upon cycling.

Synthesis of hierarchically radiated SAPO-11/Silica composites to boost n-alkane hydroisomerization

Hierarchically radiated SAPO-11 molecular sieves (RS-11-x, x was the initial SiO2/Al2O3 molar ratio) were prepared by employing different amounts of un-calcined radiated mesoporous SiO2 nanoparticles (RMSNs) as silicon source and template, and the corresponding Pt-based catalysts were applied for n-decane hydroisomerization. During the synthesis of RS-11-x, RMSNs were hydrolyzed into active Si species slowly due to the supporting of CTAB in their channels, and these active Si species interacted with Al and P species on the RMSNs to generate SAPO-11 crystal nuclei. Ultimately, hierarchical SAPO-11 molecular sieves with radiated morphologies were dispersed on the RMSNs. Among RS-11-x, RS-11-0.4 possessed the greatest medium and strong Brønsted acid sites (MSBAS) content (14.9 μmol/g) as well as superior external surface area (247 m2 g−1) and mesopore volume (0.433 cm3 g−1). Furthermore, compared with the SAPO-11 synthesized by tetraethyl orthosilicate (TEOS) and the mixture of CTAB and TEOS as silicon precursors, respectively, RS-11-0.4 possessed a larger external surface area, a higher mesopore volume and the optimal MSBAS content. Consequently, the Pt/RS-11-0.4 catalyst showed a higher selectivity of branched C10 isomers (93.5%), a better selectivity of multi-branched C10 isomers (33.8%), and a lower cracking selectivity (6.3%) than the counterpart catalysts. This work offers a new strategy for preparing hierarchical molecular sieves with superior catalytic performances.

Green synthesis of Kenaf-based activated carbons with excellent rate capability and cycle-life via hydrothermal-co-activation process for high-performance capacitive energy storage

The invention of high-performance electrode materials through a simple and green approach is always important for energy storage applications. Herein, we have prepared highly porous activated carbons (ACs) from biomass kenaf (KF) by hydrothermal and steam activation methods. A number of optimization experiments, such as hydrothermal pre-treatment (100, 150 and 200 °C), steam activation temperature (600, 700, 800, and 900 °C) and time of steam flow (15, 30, 60 and 90 min) were performed to control the specific surface area, micro- and/or meso-pores, total pore volume for an excellent electrochemical performance. The as-obtained porous ACs exhibited a high specific surface area (∼1733 m2/g) with high total pore volume (∼0.916 cm3/g) and high mesopore volume (∼28.4%), which are beneficial for the excellent double layer formation over the surface of activated electrode and also provide transport channel for an effective diffusion of electrolyte ions. The as-derived ACs were used as electrode materials for the fabrication of symmetric supercapacitor device in 6 M KOH. The fabricated device exhibited a high energy density of 4.86 Wh kg−1 at power density of 2500 W kg−1 with outstanding stability (∼96.3%) over 10,000 charge-discharge cycles.

Preparation of Co-C/N flower-like single-atom catalysts via TCPP coordination confinement for enhanced activation of peroxymonosulfate

The design and preparation of highly efficient advanced oxidation processes (AOPs) catalysts is a crucial research area in the field of water pollution control. Herein, a single-atom AOP catalyst Co-N/C material (TPM-650) has been synthesized through the pyrolysis of the flower-shaped Co-TCPP MOF precursor, which is designed based on coordination confinement with TCPP. HAADF-STEM image analysis confirms the uniform distribution of single Co atoms throughout the TPM-650 material, which served as the highly efficient catalytic centers and can achieve 99.99% catalytic degradation of MG dyes in 24 min with only trace dosage ([TPM-650] = 1 mg/L, pseudo-first-order kinetic model, Kobs=0.302 min−1) and low leaching of Co ions (0.348 μg/L). Under optimal condition, the degradation of MG exhibits a high turnover number (dTON) of 68.5 mmol h−1 gcat−1 and a significant reduction in total organic carbon (TOC) by 58.7%. Radical quenching experiments and EPR measurements demonstrated that various reactive oxygen species (•SO4−, •OH, 1O2, MIV(O)/MV(O)) contributes to accelerating MG degradation. The enhanced efficiency and stability were attributed to the ultrathin layer supported single-atom Co-N/C structure, high mesopore volume, and synergy between the catalyst and peroxymonsulfate (PMS) with a synergy index of 16.5. This study not only reports a highly efficient and stable advanced oxidation catalyst Co-N/C, but also confirms that the nitrogen-coordinated Co sites are the primary active sites responsible for PMS activation; thus providing valuable insights into designing efficient transition metal-based AOP catalyst via coordination method for environmental remediation.

Construction of N-Rich Aminal-Linked Porous Organic Polymers for Outstanding Precombustion CO2 Capture and H2 Purification: A Combined Experimental and Theoretical Study.

A large number of scientific investigations are needed for developing a sustainable solid sorbent material for precombustion CO2 capture in the integrated gasification combined cycle (IGCC) that is accountable for the industrial coproduction of hydrogen and electricity. Keeping in mind the industrially relevant conditions (high pressure, high temperature, and humidity) as well as good CO2/H2 selectivity, we explored a series of sorbent materials. An all-rounder player in this game is the porous organic polymers (POPs) that are thermally and chemically stable, easily scalable, and precisely tunable. In the present investigation, we successfully synthesized two nitrogen-rich POPs by extended Schiff-base condensation reactions. Among these two porous polymers, TBAL-POP-2 exhibits high CO2 uptake capacity at 30 bar pressure (57.2, 18.7, and 15.9 mmol g-1 at 273, 298, and 313 K temperatures, respectively). CO2/H2 selectivities of TBAL-POP-1 and 2 at 25 °C are 434.35 and 477.93, respectively. On the other hand, at 313 K the CO2/H2 selectivities of TBAL-POP-1 and 2 are 296.92 and 421.58, respectively. Another important feature to win the race in the search of good sorbents is CO2 capture capacity at room temperature, which is very high for TBAL-POP-2 (15.61 mmol g-1 at 298 K for 30 to 1 bar pressure swing). High BET surface area and good mesopore volume along with a large nitrogen content in the framework make TBAL-POP-2 an excellent sorbent material for precombustion CO2 capture and H2 purification.

Engineered cellulose-based porous carbon adsorbents for superior gas adsorption and selective separation of CH4/H2 and CH4/N2

Adsorption and separation of methane from turquoise hydrogen and coalbed methane is becoming an important method for using unconventional natural gas. Adsorbent performance determines this technique. In this regard, the cellulose-based (Cell-PC) adsorbents were engineered by a facile process with a one-pot calcination method without solvent and an activating reagent-free like KOH with an economical and green approach for CH4/H2 and CH4/N2 separation. The series of adsorbents were synthesized, such as Cell-100, U-Cell-111, O-Cell-111, O-Cell-112, O-Cell-113, and O-Cell-113-a, from cellulose with urea/oxalic acid and sodium hydrogen carbonate, which helps to create pore structure. All adsorbents were characterized by several techniques, including XRD, SEM, XPS, and BET. All Cell-PC adsorbents were used to systematically investigate adsorption studies for CH4, N2, and H2. The O-Cell-113-a adsorbent demonstrated a superior CH4 uptake capacity of 52.75 cm3/g at 273 K and 37.92 cm3/g at 298 K under 100 kPa. It was attributed to the synergistic role of high surface area, mesopore volume, micropore volume, morphology, and surface functional group. However, the O-Cell-113-a showed lower adsorption for N2 and was unable to adsorb H2 at 298 K, indicating the adsorbent has selective adsorption properties for CH4. Furthermore, the ideal adsorbed solution theory (IAST) model was used to calculate the selectivity of CH4/N2, which was found to be around 13.78 at 273 K and 12.64 at 298 K, which is higher than most previously reported porous carbon. The isosteric heat of adsorption of O-Cell-113-a adsorbent was further calculated for CH4 and N2.

Hierarchical SAPO-34 Catalysts as Host for Cu Active Sites.

Cu-containing hierarchical SAPO-34 catalysts were synthesized by the bottom-up method using different mesoporogen templates: CTAB encapsulated within ordered mesoporous silica nanoparticles (MSNs) and sucrose. A high fraction of the Cu centers exchanged in the hierarchical SAPO-34 architecture with high mesopore surface area and volume was achieved when CTAB was embedded within ordered mesoporous silica nanoparticles. Physicochemical characterization was performed by using structural and spectroscopic techniques to elucidate the properties of hierarchical SAPO-34 before and after Cu introduction. The speciation of the Cu sites, investigated by DR UV-Vis, and the results of the catalytic tests indicated that the synergy between the textural properties of the hierarchical SAPO-34 framework, the high Cu loading, and the coordination and localization of the Cu sites in the hierarchical architecture is the key point to obtaining good preliminary results in the NO selective catalytic reduction with hydrocarbons (HC-SCR).

Removal of Paracetamol and Cu2+ from Water by Using Porous Carbons Derived from Agrowastes

Dende and babassu coconuts are largely used in tropical countries, namely in Brazil, for the extraction of oils from kernels. The remaining biowastes are industrially processed to produce porous carbons (PCs). PCs derived from dende and babassu biowastes and produced at an industrial scale have been characterized by textural, chemical, and ecotoxicological parameters. A commercial activated carbon (CC) of mineral origin has been used as a benchmarking material. Although the CC sample presented a higher surface area (SBET = 1083 m2/g), the PCs derived from the biowastes were richer in micropores (Vmicro = 0.25–0.26 cm3/g), while the CC carbon presented wider pore size distribution with a higher mesopore volume (Vmeso = 0.41 cm3/g). All the adsorbents used in this work have shown a non-acute ecotoxic behavior for the bacterium Vibrio fischeri (EC50-30 min > 99% v/v). The adsorbents have been tested for paracetamol and Cu2+ adsorption in mono- and bicomponent solutions. The uptake capacities of paracetamol (qe, 98–123 mg g−1) and Cu2+ (qe, 15–18 mg g−1) from monocomponent solutions were similar to the ones obtained in the bicomponent solutions, indicating no competition or cooperative effects but a site-specific adsorption. This finding represents an advantage for the removal of these adsorbates when present in the same solution as they can be adsorbed under similar rates as in the single systems. Paracetamol adsorption was related to micropore filling, π-π interactions, and H-bonding, whereas Cu2+ removal was attributed to the cation exchange mechanism and complexation to the hydroxyl groups at the carbons’ surface.

Fabrication of N-doped micro-mesoporous carbons from industrial alkali lignin with urea assistance for high-efficiency adsorption of methylene blue

N-doping is a prospective strategy to improve the adsorption efficiency of adsorbents. Herein, N-doped porous carbons (PCs) were synthesized from industrial alkali lignin (IAL) with urea assistance for adsorbing methylene blue (MB). The nitrogen content and pore structure could be adjusted by changing urea dosage. The PCs were characterized via scanning electron microscopy (SEM), N2 adsorption-desorption experiments, Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and Zeta potential. The optimized weight ratio of urea to IAL was 1:1. NLC-1 synthesized under this condition possessed high micropore volumes (Vmicro) and mesopore volumes (Vmeso), namely 0.3531 and 0.3480 cm3/g, respectively, and the specific surface area (SSA) of NLC-1 reached 1131 m2/g. The adsorption capacities of PCs for MB were compared and discussed. Notably, the as-obtained NLC-1 exhibited the highest adsorption capacity of 785.8 mg/g. This was attributed to the pore filling and the appropriate N content (3.780%). The adsorbing process of MB onto NLC-1 was well reproduced by the Langmuir model. Furthermore, the kinetic data conformed to the pseudo-second-order (PSO) model, and the MB adsorption process was spontaneous according to the thermodynamic parameters. Overall, this study indicates that PCs from IAL have a great potential for MB adsorption.

Wood xerogel for fabrication of high-performance transparent wood

Optically transparent wood has been fabricated by structure-retaining delignification of wood and subsequent infiltration of thermo- or photocurable polymer resins but still limited by the intrinsic low mesopore volume of the delignified wood. Here we report a facile approach to fabricate strong transparent wood composites using the wood xerogel which allows solvent-free infiltration of resin monomers into the wood cell wall under ambient conditions. The wood xerogel with high specific surface area (260 m2 g–1) and high mesopore volume (0.37 cm3 g–1) is prepared by evaporative drying of delignified wood comprising fibrillated cell walls at ambient pressure. The mesoporous wood xerogel is compressible in the transverse direction and provides precise control of the microstructure, wood volume fraction, and mechanical properties for the transparent wood composites without compromising the optical transmittance. Transparent wood composites of large size and high wood volume fraction (50%) are successfully prepared, demonstrating potential scalability of the method.

Finding the Compromise between Brønsted Acidity and Mesoporosity in Hierarchical ZSM‐5 Zeolites

AbstractMesoporous ZSM‐5 catalysts were prepared from a commercial ZSM‐5 (Si/Al=15), using a 2‐step micelle‐templating procedure. By varying the NaOH/Si synthesis ratio in the range of 0.3‐0.7, ZSM‐5 catalysts with different textural and acidic properties were obtained. Increasing the NaOH/Si ratio in the synthesis gel leads to zeolites that feature reduced number of Brønsted acid sites, but higher mesopore volume, which allows for reducing the diffusion path length. In order to assess the best compromise between Brønsted acidity and mesopore volume two test reactions were run. The alkylation of phenol with tert‐butyl alcohol allowed to evidence the accessibility of bulky molecules to active sites. The esterification of benzyl alcohol with hexanoic acid allowed to probe the specificity of Brønsted acid sites in ZSM‐5. The best compromise was found for micro‐/mesoporous ZSM‐5 catalysts prepared with the ratio 0.38<NaOH/Si<0.5.