Micropore Volume Research Articles

Prediction and Optimization Design of Porous Structure Properties of Biomass-Derived Biochar Using Machine Learning Methods

Biochar produced from biomass by pyrolysis and activation is a platform porous carbon material that has been widely used in many areas. The porosity properties of biochar such as specific surface area (SSA), total pore volume (Total_PV), micropore volume (Micro_PV), mesopore volume (Meso_PV), and average pore size (Average_PS) are essential to biochar applications. Although previous machine learning (ML) models can precisely predict SSA and Total_PV, these models are unable to comprehensively predict the other porosity characteristics. More importantly, activation, which is a critical process for preparing high-porosity biochar, was generally not considered in previous studies. Here, six single-target models were established first based on pyrolysis & activation conditions for the prediction of SSA, Total_PV, Micro_PV, Meso_PV, Average_PS, and yield, obtaining test R2 of 0.89, 0.86, 0.88, 0.89, 0.76 and 0.91, respectively. Then, a multi-target model was established for simultaneous prediction with an average test R2 of 0.87. ML model interpretation indicated agent type and ratio were crucial to porosity properties. Finally, activation and direct pyrolysis biochar production optimum schemes were derived from ML model for a high porosity. Favorable experimental verification results were obtained with validation R2 of 0.98, indicating the great potential of using ML for biochar engineering.

Adsorption equilibria and kinetics of CO2 and N2 on silica-alumina gels for reducing gas production by CO2 removal from iron flue gases

In industrial fields, hydrogen-containing flue gases generally contain a certain amount of CO2 and N2. After removing CO2, the raffinate gases can be used in various applications to mitigate carbon emissions. Furthermore, the concentrated CO2-rich extract contributes to efficient CO2 capture. Silica-alumina gel can be a high potential adsorbent because of its high CO2 adsorption capacity and energy-saving desorption. Three different silica-alumina gels with different amounts of alumina (FJ, KD, and WS) were compared to study the impact of the alumina content on the adsorption characteristics. The adsorption behaviors of CO2 and N2 were measured at 293K, 308K, and 323K at pressures up to 1000 kPa. The isotherms correlated with the dual-site Langmuir model, showing that the adsorption capacity for CO2 was much higher than that for N2 across all the adsorbents. The surface areas and adsorption capacities followed the opposite order of alumina content: FJ > KD > WS. However, the difference intervals in the isotherms did not align consistently with the alumina content, but the micropore volume changed by alumina contributed highly to the adsorption capacity. In the adsorption kinetic analysis, the diffusional time constants and kinetic parameters in a non-isothermal adsorption kinetic model showed minor dependence on pressure and temperature. The adsorption rate was higher for N2 than for CO2. It increased with alumina content, following the order WS > KD >> FJ. The results contribute to the establishment of guidelines for the selection of silica-alumina gel and the design of the adsorption process.

Promising honeycombed cork activated carbon for high desalination performance brackish water treatment

Cork activated carbon (CAC), derived from natural cork, was successfully prepared through two steps of carbonation and activation, and used for desalinating brackish water. The CAC presents a uniform honeycomb structure composed of porous carbon nanoflakes (200–300 nm) and large specific surface area (SSA) (2680 m2 g−1), offering transport channels and a large number of adsorption sites to NaCl solution. The CAC showed excellent capacitance (116 F g−1), small internal resistance and better charge-discharge performance. Moreover, the optimized CAC showed high desalting capacity (9.44 mg g−1), charge efficiency (46.72 %), and lower energy consumption (54.19 Wh m−3) in the desalination process, superior to that of the reported biomass-based activated carbons, which can be attributed to the stable honeycomb structure, high microporous volume (0.86 cm3·g−1) and large pore size (2.43 nm). This investigation demonstrates the potential application of cork granules-based CAC electrodes in the field of desalination.

The effect of humidity on the enhanced CO2 adsorption of amine-functionalized microporous activated carbon.

Cost-effective and environmentally friendly sorbents were created for capturing CO2 by incorporating monoethanolamine (MEA) and tetraethylenepentamine (TEPA) onto a microporous activated carbon (AC) material. The application of a KOH reagent enhanced the surface area and pore volume of the carbon material. The BET, SEM, EDX, and FTIR techniques were employed to analyze the structural and surface properties of the developed samples. Raw AC possessed the highest surface area and largest micropore volume equal to 786 m2/g and 0.33 cm3/g, respectively. The amine impregnation increased the nitrogen content of the carbon material, but it also significantly reduced the BET surface area and total pore volume, which are primarily responsible for physically adsorbing CO2 towards ACs. The CO2 adsorption performance of the raw and impregnated ACs was experimentally evaluated using thermogravimetric analysis (TGA) at different adsorption temperatures (25 and 50 °C) and CO2 concentrations (10 and 90 vol.%). The findings demonstrated that the raw AC exhibited the highest capacity for CO2 adsorption. Specifically, at a temperature of 25 °C and pressure of 1 bar (10 vol.% CO2, N2 balance), the raw AC achieved an uptake of 1.2 mmol/g, which was 60.3% and 79.3% higher compared to the CO2 uptake of MEA-AC (0.5 mmol/g) and TEPA-AC (0.3 mmol/g), respectively. It is surprising that the combined uptake of CO2 + H2O increased by 12.5 and 23.4 wt.% (equivalent to 7 and 13 mmol/g) for MEA-AC and TEPA-AC, respectively, when humid flue gas was taken into account under the conditions of 50 °C, with 10 vol.% CO2, 4 vol.% H2O, and N2 balance. These results indicate that the presence of H2O facilitates the chemisorption of CO2 by the novel and highly promising carbon-based sorbent prepared in this study, leading to an increased capacity for adsorbing CO2 under water vapor containing flue gases.

Enhanced removal of trace-level per- and polyfluoroalkyl substances (PFAS) from drinking water using granular activated carbon (GAC): the role of ozonation.

Granular activated carbon (GAC) is a promising approach for removing per- and polyfluoroalkyl substances (PFAS) from drinking water. However, GAC filters usually suffer early PFAS breakthroughs due to the competition between PFAS and natural organic matter (NOM) during sorption. The present study investigated the possibility of using ozonation to enhance the GAC performance for PFAS removal. Rapid-small-scale-column tests were performed for three GACs using filtered or filtered and ozonated water. NOM was fractionated using liquid chromatography-organic carbon detection (LC-OCD), and 76 ambient PFAS were quantified using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS). Although ozonation did not remove either NOM or PFAS, it altered their composition in water. Ozonation reduced the hydrophobicity and the molecular size of natural organic matter (NOM). On the other hand, ozonation oxidized some PFAS precursors, leading to a higher total detected PFAS concentration in the filtered and ozonated water than in filtered water (10.2 ± 0.7 ng/L vs. 9.5 ± 0.7 ng/L). The impact of ozonation on GAC performance for NOM and PFAS removal mainly depended on GAC properties. GAC with a lower micropore volume showed an improvement in NOM and PFAS removal when ozonation was applied, approaching the performance of GACs with higher micropore volumes.

Porous Molecular Crystals Derived from Cofacial Porphyrin/Phthalocyanine Heterodimers.

Porphyrin‐based porous materials are of growing interest as heterogeneous catalysts especially for reactions that are of importance to sustainability. Here we demonstrate that porous molecular crystals can be prepared by the simple co‐crystallisation of tetraphenylporphyrin (TPP) with octa(2’,6’‐di‐isopropylphenoxy) phthalocyanine or some of its metal complexes [(dipPhO)8PcM; M = H2, Al‐OH, Ti=O, Mn‐Cl, Fe‐Cl, Co, Ni, Cu, Zn, Ga‐Cl, Ag, In‐Cl or Au‐Cl]. This process is facilitated by the efficient formation of the supramolecular heterodimer between TPP and (dipPhO)8PcM, which is driven by the complementary shape and symmetry of the two macrocycles. The (dipPhO)8PcM component directs the crystal structure of the heterodimers to form Phthalocyanine Nanoporous Crystals (PNCs) of similar structure to those formed by (dipPhO)8PcM alone. The incorporation of TPP appears to partially stabilise the PNCs towards the removal of included solvent and for cocrystals containing (dipPhO)8PcCo stability can be enhanced further by the in‐situ addition of 4,4‐bipyridyl to act as a “molecular wall tie”. These stabilised PNC/TPP cocrystals have a Brunauer‐Emmett‐Teller surface area (SABET) of 454 m2 g‐1 and a micropore volume (Vmp) of 0.22 ml g‐1. The reactivity of both macrocycles within the PNC/TPP co‐crystals are demonstrated by in‐situ metal insertion.

Porous Molecular Crystals Derived from Cofacial Porphyrin/Phthalocyanine Heterodimers.

Porphyrin-based porous materials are of growing interest as heterogeneous catalysts especially for reactions that are of importance to sustainability. Here we demonstrate that porous molecular crystals can be prepared by the simple co-crystallisation of tetraphenylporphyrin (TPP) with octa(2',6'-di-isopropylphenoxy) phthalocyanine or some of its metal complexes [(dipPhO)8PcM; M = H2, Al-OH, Ti=O, Mn-Cl, Fe-Cl, Co, Ni, Cu, Zn, Ga-Cl, Ag, In-Cl or Au-Cl]. This process is facilitated by the efficient formation of the supramolecular heterodimer between TPP and (dipPhO)8PcM, which is driven by the complementary shape and symmetry of the two macrocycles. The (dipPhO)8PcM component directs the crystal structure of the heterodimers to form Phthalocyanine Nanoporous Crystals (PNCs) of similar structure to those formed by (dipPhO)8PcM alone. The incorporation of TPP appears to partially stabilise the PNCs towards the removal of included solvent and for cocrystals containing (dipPhO)8PcCo stability can be enhanced further by the in-situ addition of 4,4-bipyridyl to act as a "molecular wall tie". These stabilised PNC/TPP cocrystals have a Brunauer-Emmett-Teller surface area (SABET) of 454 m2 g-1 and a micropore volume (Vmp) of 0.22 ml g-1. The reactivity of both macrocycles within the PNC/TPP co-crystals are demonstrated by in-situ metal insertion.

Efficiency of the TEMJOUHERT date palm kernel as activated carbon in wastewater treatment for the Ghardaia region

This study aims to determine the potential for using activated carbon prepared by local agricultural waste for the treatment of wastewater loaded with organic pollutants. The activated carbon was prepared by chemical activation using phosphoric acid H3PO4 at an “85%” concentration, from local date kernels TEMJOUHERT (TMG) from the Ghardaïa region, Algeria. The activated carbon synthesis yield is equal to 28.56%. The adsorbent prepared was characterized by determining its physical and chemical characteristics, in particular the bulk density, the ash content, the iodine number, the surface functions by the Boehm method and the pH at the point of zero charge. Thus the textural properties are determined by scanning electron microscopy SEM and the Burnauer-emmett-Teller (BET). The surface area and micropore volumes of activated carbon TMG; were found to be 639.9190 m2/g and 0.420779 cm3/g respectively. All the results obtained from the treatment of wastewater from the Atteuf "kef doukhane area in the Ghardaia region. are clear that: the best pollutant removal rates are 84.75% for PO3-4; 85.21% for COD and 74.55% for NH4+ by activated carbons; using a mass of 1g of adsorbent per 100 ml of water, 90 min contact time and 250rpm stirring speed.

Competitive adsorption of polycyclic aromatic hydrocarbons on phosphorus tailing-modified sludge biochar provides mechanistic insights.

Biochar has been widely used to solve the wastewater pollution of polycyclic aromatic hydrocarbons (PAHs). However, the competition of PAHs with different benzene ring numbers (e.g., phenanthrene [Phe], pyrene [Pyr], and benzo[a]pyrene [BaP]) for adsorption sites on biochar has received little attention. In this study, biochar was produced by co-pyrolysis of sludge and phosphorus tailing at different temperatures (300, 500, or 800°C) to adsorb PAHs. The results show that phosphorus tailing increased the adsorption of PAH by increasing the biochar's BET surface area (SBET), micropore volume, hydrophobicity (at low temperatures) and aromaticity (at high temperatures). The maximum adsorption capacities were 29.90µmol/g for Phe, 25.58µmol/g for Pyr and 20.45µmol/g for BaP, respectively. Importantly, the types and functions of groups involved in the adsorption of various PAHs were discussed. Adsorption of Phe and Pyr on the biochar mainly involved C=O and C-O-C functional groups, and there was a certain degree of competition between these PAHs for those sites. In contrast, BaP mainly adsorbed at C-OH and C=C moieties, without competing with Phe or Pyr at C-OH sites. The competitive edge of BaP was also stronger than that of Phe and Pyr on C=C functional groups. The adsorption mechanisms involving pore filling, hydrophobic interactions, and π-π interactions governed the adsorption of the evaluated PAHs. Overall, the adsorption of PAHs on biochar followed a heterogeneous chemical adsorption process.

Amino acid assisted-construction of 2D-hierarchical MFI zeolites for adsorption of rhodamine B

Hierarchical and two-dimensional (2D) zeolites have drawn much attention in catalysis and separation process due to their fast mass transfer. However, the facile manipulation in controllable mesopore volumes and morphologies for hierarchical nanozeolites is full of challenges. Herein, a facile strategy is presented for the synthesis of single-crystalline 2D hierarchical MFI zeolite nanosheets (HNSs) with tunable mesopore volumes through the amino acid-assisted crystallization of nucleated amorphous silicon precursors (NASPs). The tailored synthesis of HNSs with controllable aspect ratios ((Lc + La)/Lb), b-axis thicknesses (a few tens of nanometers) and mesopore volumes is achieved by adjusting the preparation of the NASPs and the amount of amino acid in the synthesis mixture. The HNSs exhibit large BET surface area (>400 m2 g-1), high micropore volume (0.16–0.18 cm3 g−1) as well as rich mesopore volume (>0.10 cm3 g−1), indicating the high crystallinity of the hierarchical zeolite nanosheets. Specially, the higher adsorption capability and faster adsorption rate for the dye (Rhodamine B) adsorption demonstrate the excellent performance of the hierarchical zeolite nanosheets, which exhibits the maximum adsorption capacity of 115.7 mg g−1. The controllable manipulation of mesoporous volumes and morphologies in MFI zeolites represents a significant contribution to the field of zeolite microstructure engineering.

Effect of silver salt type on the physicochemical properties and antimicrobial activity of solid‐state Ag‐exchanged zeolites

AbstractThe silver‐exchanged zeolites were created using a solid‐state ion exchange method with silver sulfate and silver nitrate salts. Various techniques, including X‐ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area analysis, scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy, were employed to examine the structure, morphology, and physical‐chemical properties of the samples. The antimicrobial effectiveness of the zeolites was tested against gram‐negative Escherichia coli and gram‐positive Staphylococcus aureus, common bacteria found in wastewater. Before the silver exchange, the original zeolite exhibited small clustered particles, but after the exchange, its shape underwent significant transformation. The original clinoptilolite did not contain any silver, whereas the silver‐exchanged samples AgSSE6% and AgNSE6% had silver contents of 2.29% and 3.80%, respectively. The XRD analysis confirmed the presence of Ag and AgO within the structure of the exchanged clinoptilolite. BET analysis indicated that the incorporation of Ag ions into the zeolite structure through ion exchange led to a reduction in surface area and micropores volume. The research findings revealed that zeolites exchanged with silver were more effective in inhibiting the growth of S. aureus, compared to E. coli. Additionally, zeolites treated with AgSO4 exhibited a wider inhibition zone against both bacteria compared to zeolites treated with AgNO3.

Effect of temperature on the radon release characteristics of red clay

Bricks and tiles crafted from fired red clay are extensively utilized in everyday construction activities. However, red clay inherently contains radon gas, a radioactive substance that could potentially endanger human health. Hence, investigating the radon emission patterns of red clay post high-temperature treatment holds significant importance. This study examines the pore structure of red clay following high-temperature treatment through nitrogen adsorption and analyzes the radon release patterns. Findings reveal that the radon release rate from red clay initially rises, then declines with increasing temperature, peaking at 200 °C, registering at 0.0127 Bq/(m2 s). The pore structure significantly influences radon exhalation, with connectivity and micropore volume demonstrating linear correlations with radon exhalation rate, with correlation coefficients of 0.96 and 0.78, respectively. This research offers valuable insights into radon radiation in structures made of red clay.

Polytriphenylamine Conjugated Microporous Polymers as Versatile Platforms for Tunable Hydrogen Storage.

Hydrogen (H2) as a fuel source presents a promising route toward decarbonization, though challenges in its storage remain significant. This study explores the synthesis and characterization of polytriphenylamine (PTPA)conjugated microporous polymers (CMPs) for H2 storage. Utilizing a combination of Buchwald-Hartwig (BH) coupling, the Bristol-Xi'an Jiaotong (BXJ) approach, and variations in monomer reactive site stoichiometry, a polymer with specific surface areas in excess of 1150 m2g-1 and micropore volume of 0.47cm3g-1 is developed. H2 storage capacities are measured, achieving excess gravimetric uptakes of 1.65 wt.% at 1bar and 2.51wt.% at 50bar and 77 K, with total capacities reaching 4.40 wt.% at 100bar and 77 K. Net adsorption isotherms reveal advantages to H2 storage using PTPA adsorbents over traditional compression up to pressures of 10bar at 77 K. High mass transfer coefficients of 4.95min-1 indicate a strong material affinity for H2. This study highlights the impact of monomer ratio adjustments on the porosity and excess, total, and net H2 adsorption capacities of PTPA-based CMPs, offering insights into the importance of a non-stoichiometric monomer concentration when developing efficient CMP-based H2 storage materials.

A modified dubinin-radushkevich model describing the cryogenic adsorption of 4He on carbon materials

The 4He and 3He adsorption characteristics of porous materials serve as important references for designing and optimizing cryogenic components or systems, including adsorption pumps, helium adsorption refrigerators, and gas-gap heat switches. In this study, various types of activated carbon and carbon nanotubes were measured for their 4He adsorption characteristics in the range of 3–20 K and 1–18000 Pa. Parameters such as micropore volume and adsorption potential energy of porous materials were analyzed through Dubinin-Radushkevich (DR) model. A modified DR model describing the monolayer adsorption of 4He on different carbon-based adsorbents was developed in this study, greatly facilitating the design of adsorption systems. Further, the 4He adsorption model was applied to gas-gap heat switches, and a numerical model of the 4He gas-gap heat switch was established, which accurately predicts the actuation characteristics of several heat switches.

Soil Physical Properties, Root Distribution, and “Ponkan” Tangerine Yield Across Different Rootstocks in a Deep Tillage Ultisol

Deep soil tillage and proper rootstock selection mitigate the root development limitations in Ultisol’s Bt horizon, enhancing the citrus yield potential. This study evaluates the root spatial distribution of three Ponkan tangerine rootstocks in Ultisol under deep tillage alongside the physical-hydric attributes and plant measurements. The experimental area underwent furrow creation, subsoiling, and hole opening for planting. The treatments included three rootstocks: “Cravo Santa Cruz” (CSC), “Sunki Tropical” (ST), and “Citrandarin Índio” (CI). Under the Ultisol preparation, these rootstocks were compared to a native forest area (FA). Three years post-initial tillage, soil samples were collected at depths of 0–0.05, 0.35–0.40, and 0.45–0.50 m from the pre-established positions. The evaluation encompassed soil dispersive clay, available water, crop water use, plant measurement, and crop yield. The root evaluation utilized the crop profile method and 2D images, with subsequent surface mapping of the root variables, number (NR), and diameter (RD) analyzed via kriging geostatistical analysis. The Ultisol showed significant changes in its physical-hydric attributes regarding structural change and more excellent clay dispersion, with a considerable contribution to the micropore volume. Deep tillage effectively improved the root spatial distribution, especially concerning the number and diameter of roots, and enhanced the water use, reflected in the vegetative growth and yield, with the rootstock CSC standing out.

Highlighting the adsorption mechanism of a fluoroquinolone antibiotic from wastewater on carbon xerogel by experiments, characterization, modelling and DFT simulation.

The application of a synthesized carbon xerogel (RFX) for the adsorptive removal from water of ciprofloxacin (CPX), a widely used fluoroquinolones-group antibiotic for humans and animals, has been reported in this work. The carbon xerogel was characterized by N2 adsorption-desorption isotherms, FTIR, Raman spectroscopy, TPD studies, elemental analysis, determination of isoelectric point (pHIEP) and scanning electron microscopy (SEM). CPX adsorption experiments were conducted in batch mode, using results obtained with F400 commercial activated carbon for comparison purposes. CPX adsorption kinetics were well-described by the pseudo-second-order model for both adsorbents and by the Elovich model in the case of F400 activated carbon. Therefore, CPX equilibrium adsorption capacity values were of 457 and 72mgg-1 for RFX xerogel and F400 activated carbon, respectively. This significant difference can be attributed to the higher specific surface area and micropores volume values of F400 carbon; in this sense, this material led to a slower CPX kinetic adsorption. Also, the Dual-site Langmuir model best-described the experimental CPX adsorption isotherms in both cases. By the adsorption studies at different solution pH, it could be concluded that several mechanisms, e.g., hydrophobic and π-π interactions, and electrostatic forces highly influenced CPX adsorption capacity. Furthermore, adsorption tests using several environmentally relevant aqueous matrices have been accomplished. In this case, a competitive effect between the natural organic matter (NOM) and the target pollutant occurred in all the tested real matrices, decreasing CPX adsorption capacity, especially remarkable for F400 activated carbon. Finally, Density Functional Theory (DFT) has been used to elucidate the interactions between CPX and adsorbents, finding a high relevance of the π-π electron donor-acceptor interactions in which CPX acts as an acceptor.

Secondary carbon skeletons constructed in porous carbon for electric double layer capacitors

In this work, a secondary skeleton was constructed by filling the larger spaces of porous carbon derived from passion fruit peels with glucose to created more carbon surface in same volume. The combined use of KOH activation and simultaneous etching of micropores on the carbon skeleton and secondary skeleton resulted in the preparation of porous carbon (PGC1-0.5) containing a large number of micropores. PGC1-0.5 have less total pore volume (0.987 cm3 g−1), but more micropore volume (0.821 cm3 g−1), different with 1.171 cm3 g−1, 0.668 cm3 g−1 of PGC1-0, which without glucose. Symmetric supercapacitor bases on PPGC1-0.5 have an obvious improvement in specific capacity (275.6 F g−1 (175 F cm−3), 0.1 A g−1) in 6 M KOH electrolyte compared to PGC1-0 (215.2 F g−1 (121.5 F cm−3), 0.1 A g−1). Additionally, the device exhibits excellent cycling performance and retained 103% of its specific capacity after 10,000 cycles and notable reduction in transfer internal resistance in comparison to the sample without glucose. This study shows that filling space with glucose to reduce macropores is an effective method for adjusting the pore size distribution of porous carbon.

Porosity Regulation of Surfactant‐Assisted Glycerol Organosolv Lignin Modified Hyper‐Cross‐Linked Polymers and Their Efficient Adsorption for Dyes From Water

ABSTRACTHere, we tried to use the natural biomass resources (lignin) to modify porous organic polymers (POPs) and expected to reduce the preparation cost and enhance the adsorption performance. Specifically, the surfactant‐assisted glycerol organosolv lignin (saGO lignin) was used as the modified agents to prepare lignin modified hyper‐cross‐linked polymers (LHCPs) by the copolymerization and Friedel‐Crafts reaction. We investigated the effect of synthesis conditions (the types and dosages of crosslinkers, the feeding amount of lignin, and so on) on the structure and adsorption performance of LHCPs. The results showed that divinyl benzene (DVB) crosslinked LHCP‐D (1041.3 m2/g) showed higher specific areas (SBET) than N,N′‐methylene diacrylamide (MBA) crosslinked LHCP‐M (183.1 m2/g), and the SBET had a certain increase with increasing the amount of DVB. Intriguingly, the SBET and micropore volume (Vmicro) of LHCPs appeared a linear decrease with the increase of lignin dosage, meanwhile, their morphology had a change from irregular block to agglomerated spherical particles, indicated their porosity and morphology can be well controlled. The Rhodamine B (RhB) adsorption experiments indicated that these LHCPs possessed fast adsorption rate (equilibrium time < 240 min) and good recycling performance, especially, LHCP‐D (lignin of 0.5 g, DVB of 1.0 g, catalyst of 3.0 g, reaction time of 10 h) showed the ultrahigh adsorption capacity, up to 743.7 mg/g. The adsorption mechanism was preliminarily investigated by X‐ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and adsorption models analysis, we found that the physical adsorption played the dominated roles by the π–π interaction, hydrogen bonding, and electrostatic interaction. This work not only offered an important reference for the high‐value utilization of lignin, but also provided an effective sustainable adsorbent for environmental remediation.

Optimized pyrolytic synthesis and physicochemical characterization of date palm seed biochar: unveiling a sustainable adsorbent for environmental remediation applications.

This study focuses on the optimization and comprehensive characterization of biochar synthesized from date palm seeds (DPS), a prevalent agricultural waste in arid regions. Using response surface methodology (RSM) with a central composite design (CCD), we optimized the pyrolysis process by investigating the effects of time (1-3 h) and temperature (600-900 °C) on critical properties such as specific surface area, pore volume, and yield. The optimized biochar, produced at 828 °C for 1.7 h, demonstrated a high specific surface area of 654.8 m2/g and well-developed microporosity. Characterization techniques, including XRD, FTIR, SEM-EDS, and BET analyses, revealed an amorphous carbon structure with graphitic domains, diverse surface functionalities, and a heterogeneous porous microstructure. The biochar's point of zero charge at pH 7.58 indicates its potential for selective adsorption of charged contaminants. The close agreement between RSM-predicted and experimental values for specific surface area (652.1 m2/g vs. 654.8 m2/g) and micropore volume (0.191 cm3/g vs. 0.190 cm3/g) validates the effectiveness of the model in optimizing biochar properties. This research highlights the potential of DPS-derived biochar as a sustainable adsorbent for environmental remediation, opening avenues for valorizing agricultural wastes and contributing to circular economy principles.

Remarkable improvement in the NOx storage ability of Pd/SSZ-13 zeolite PNA via a facile pretreatment strategy

A facile strategy was employed to pretreat Pd/SSZ-13 zeolite obtained via the initial-impregnated method under a microwave field, aiming to greatly enhancing the NOx storage-release ability. By investigating the effect of microwave treatment parameters (power, atmosphere and time) on the improvement of PNA performance, the optimal conditions were determined (175 W, 10 % O2/N2, 15 min). Under these conditions, the Pd/SSZ-13 exhibited an enhanced NOx adsorption and desorption amount to 2.60 and 2.38 times, respectively, compared to the untreated sample after three cycles of NO-TPD. Deeper insights into the variations in Pd/SSZ-13 properties induced by the microwave radiation were clarified through a series of characterizations. The micropore surface area of Pd/SSZ-13 zeolite activated by microwave increased by 3.91 %, and the micropore volume also improved by 3.85 %, which might facilitate the adhesion of more active Pd species to the materials surface, and aid in the dispersion of PdOx clusters into the zeolite channels. After microwave activation, the average particle size of Pd decreased from 10.09 nm to 7.08 nm. Particularly, the content of Pd(II) species such as Pd2+, [Pd(OH)]+ and PdO as active NOx adsorption sites enhanced from 66.68 % to 68.93 %. Additionally, the microwave treatment not only increased the number of Lewis and Brønsted acid sites, but also strengthened the interaction between NOx molecules and the zeolite skeleton. The above reasons collectively promoted the NOx storage-release properties of Pd/SSZ-13 zeolite, showing that the microwave pretreatment is a highly efficient strategy for improving the performance of PNA materials.