Selective Adsorption Research Articles

Construction of hydrophobic HKUST-1 in wood with selective adsorption performance for toluene and moisture blends

The effect of moisture on the volatile organic compound (VOC) adsorption on biomass-derived metal–organic framework composites is significant in practical applications. In this study, wood-based metal organic frameworks (MOF199-W) and hydrophobic MOF199-W (HMOF199-W) were developed using HKUST-1 (MOF199) and long alkyl chains to investigate the adsorption performance of toluene and enhance the selectivity of adsorption under high humidity conditions. The results demonstrated that HKUST-1 could be anchored onto the surface of wood vessels and fibers through coordination with Cu2+, resulting in an improved surface area in comparison to natural wood. The toluene adsorption capacity of MOF199-W with a 20 % loading was comparable to that of an equivalent amount of MOF199, with adsorption capacities of 323.5 mg/g and 369.9 mg/g, respectively. Further, the Yoon-Nelson model was found to adequately describe the dynamic adsorption process. Following the introduction of long alkyl chains, MOF199 and MOF199-W were endowed with strong hydrophobic character (water contact angle of 107.0◦, 104.0◦, and water uptake of 30.5 mL/g, 55.3 mL/g). With the increase in humidity, the adsorption performance of MOF199 and MOF199-W for toluene sharply decreased, but HMOF199 and HMOF199-W still maintained the adsorption capacities at 304.7 mg/g and 226.7 mg/g, even under 80 % RH conditions. Therefore, HMOF199-W has shown great potential in wooden building materials with the ability for toluene capture under humid conditions.

Stimuli-Responsive Molecularly Imprinted Polymers: Mechanism and Applications.

Molecularly imprinted polymers (MIPs) are very suitable for extraction, drug delivery systems, and sensors due to their good selective adsorption ability, but the difficulty of eluting templates during synthesis and the limitation of application scenarios put higher demands on MIPs. Stimuli-responsive MIPs (SR-MIPs) can actively respond to changes in external conditions to realize various functions, which provides new ideas for the further development of MIPs. This paper reviews the multiple response modes of MIPs, including the common temperature, pH, photo, magnetic, redox-responsive and rare gas, biomolecule, ion, and solvent-responsive MIPs, and explains the mechanism, composition, and applications of such SR-MIPs. These SR-MIPs and the resulting dual/multiple-responsive MIPs have good selectivity, and controllability, and are very promising for isolation and extraction, targeted drug delivery, and electro-sensor.

Dodecylphosphonic acid for the separation of spodumene and albite: flotation behavior and adsorption mechanism

Spodumene is an important lithium-bearing mineral, that is associated with albite and difficult to separate because of their similar surface chemical properties. Traditional fatty acid collectors often have issues, such as poor selectivity or weak collector ability, and thus developing efficient spodumene collectors is essential. In this study, the phosphonic acid surfactant dodecylphosphonic acid (DDPA) was first used as a single collector for the flotation separation of spodumene and albite, showing good selectivity and collection performance. Then, separation and adsorption mechanisms were studied using various characterization methods, including diffuse reflectance infrared Fourier transform spectroscopy, total organic carbon adsorption measurements, X-ray photoelectron spectroscopy, and zeta potential tests. Flotation tests showed that the recovery for spodumene can reach approximately 80% through single-mineral flotation under the following conditions: activation without metal ion, neutral pulp pH of 6.5–7.0, and DDPA dosage of 4 × 10−4 mol/L. By contrast, the recovery of albite was only approximately 10%. The recovery for Li2O in the artificial mixed ore test was 75.03%, and the grade was 6.30%. The separation of spodumene and albite was due to the selective adsorption of DDPA on the surface of spodumene, and more DDPA were adsorbed on the surface of spodumene than on albite under the same conditions. Adsorption mechanism analysis indicated that Al and O on the mineral surface were the active sites for DDPA adsorption. Combined with the species distribution, DDPA existed in various forms in different aqueous environments, indicating that DDPA was mainly adsorbed onto the mineral surface through chemisorption and hydrogen bonding. In summary, DDPA can be used as an effective collector for spodumene.

Enhanced removal of biolabile oxygen-depleted dissolved organic matter by coagulation-adsorption process Improves biological stability of reclaimed water

Ensuring biological stability, signifying the maintenance of an unchanged bacterial concentration and composition during water distribution, is essential for mitigating the microbial hazards of reclaimed water. However, the interplay between chlorine-resistant bacteria (CRB) regrowth and molecular transformation of biodegradable organic matter in chlorinated reclaimed water distribution system remain unclear. This work investigated the transformation of dissolved organic matter (DOM) in reclaimed water treated by coagulation and by coagulation-adsorption over a 20-day incubation following chlorination, as well as its interactions with CRB through high-resolution mass spectrometer and high-throughput sequencing. The DOM biotransformation profile and DOM-bacteria interaction network collectively revealed the overall substrate preference and metabolic pattern of CRB (e.g., Methylobacterium-Methylorubrum, Acidovorax, and Sphingomonas), which evinced a propensity for utilizing oxygen-depleted DOM (O/C < 0.5) and producing oxygen-enriched DOM (O/C > 0.4). The incorporation of powdered activated carbon during coagulation markedly decreased the level of biodegradable DOM (4.33 mg C/L) and subsequently retarded the regrowth of CRB by one day compared to coagulation alone, attributable to the selective adsorption of DOM molecules with low O/C onto the activated carbon. This work underscores the critical role of the enhanced removal of oxygen-depleted DOM in ameliorating the biological stability of waters.

Waste tea as absorbent for removal of heavy metal present in contaminated water

The goal of this study is to investigate the efficacy of tea-derived absorbents for the removal of heavy metals from contaminated water. For this, absorbents were prepared from milk tea (MT) waste, Ilam tea (IT) waste, and various types of tea leaves, including Immature (IML), mature (ML), and old leaves (OL). The characterization of the absorbents revealed distinct physical and chemical properties from X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), with varying degrees of effectiveness observed across different absorbent types. Heavy metal removal efficiency was assessed using a chemical-free UV-spectrophotometer. The results show that the maximum removal efficiency for Cd using the IT absorbent reaches up to 82.14 % with 100 ppm cetyltrim ethylammonium bromide (CTAB), while the minimum removal efficiency is 32.14 % using the OL absorbent with 20 ppm CTAB. For Zn, the OL absorbent demonstrates a maximum removal efficiency of 52.59 % with 100 ppm CTAB, whereas the minimum efficiency is 3.70 % using the ML absorbent with 20 ppm CTAB. For Ni, the highest removal efficiency is achieved with the ML absorbent, reaching up to 97.73 % with 100 ppm CTAB, and the lowest is 31.82 % with the MT absorbent with 20 ppm CTAB. The addition of a catalyst further enhanced removal efficiencies in both absorbents and metals. Also, the removal of heavy metal ions using 0.05 g of tea absorbent combined with CTAB at varying concentrations. Results show that the addition of 20 ppm and 100 ppm CTAB significantly reduces metal ion concentrations from an initial 100 mg/L. The metal ion concentration decreases as CTAB concentration increases, demonstrating the effectiveness of CTAB in enhancing the absorption capacity of tea absorbent for heavy metal removal. The investigation of selective adsorption of Ni, Zn, and Cd by an adsorbent, revealing competitive adsorption behavior with Ni and Zn being adsorbed more rapidly than Cd, suggesting the impact of metal ion interference on adsorption efficiency. However, limitations were observed with certain absorbent types; for instance, immature leaves did not effectively remove Ni. Overall, this study underscores the potential of tea-derived absorbents as sustainable solutions for mitigating heavy metal pollution in industrial wastewater. Further research is needed to optimize absorbent formulations and explore their applicability in real-world environmental remediation scenarios.

One-step green synthesis of melamine-modified cellulose nanofiber composite aerogels for efficient removal of Pb(II) and Cu(II): Experiments and DFT calculations

A composite aerogel (CGMA) with high porosity (98.32 %) and multiple active sites was prepared for the adsorption of Pb(II) and Cu(II) by sol-gel combined with freeze-drying process using melamine and (3-Glycidyloxypropyl)trimethoxysilane as cellulose nanofiber modifying materials. Characterized by SEM-EDS, XPS, FTIR, BET, MIP and TG, CGMA has a hierarchical pore structure and abundant adsorption sites. At pH = 6, the adsorption reached equilibrium within 120 min, following the Pseudo second-order kinetic model and the Langmuir model, with maximum capacities of 268.1 mg/g for Pb(II) and 152.6 mg/g for Cu(II). The process was primarily governed by homogeneous chemisorption. The coexisting ion, organic matter, and water quality experiments confirmed the excellent anti-interference properties of CGMA. Competitive adsorption experiments showed that CGMA has excellent selective adsorption performance for Pb(II). After 5 cycles, Pb(II) and Cu(II) adsorption performance decreased to 79.21 % and 83.40 %, respectively. FTIR, XPS, DFT and RDG analysis showed that amino groups and oxygen-containing groups were the main sites of adsorption. CGMA forms coordination bonds and complexes with Pb(II) and Cu(II) via amine and oxygen groups and adsorbs via electron transfer, hydrogen bonding, and van der Waals forces, with Pb(II) being more selective. CGMA has good prospects for application in heavy metal ion treatment.

Processing of water regenerable PLA@HNT nanocomposite via melt extrusion for selective adsorption of aqueous phase tetracycline

Processing of water regenerable PLA@HNT nanocomposite via melt extrusion for selective adsorption of aqueous phase tetracycline

Carboxyl carbon nanotubes strengthened tailorable chitosan imprinted polymers for selective adsorption of dibenzothiophene in hydrogenated diesel

Selectively capturing and adsorbing high-valued dibenzothiophene (DBT) from hydrogenated diesel is a meaningful and economic tactic for sulfide resource recovery. The design of efficient adsorbents with desirable adsorption capacity, high selectivity and simple retrieval is still challenging. In this work, an imprinting polymerization coupling freeze-drying approach was adopted to elaborately prepare carboxyl carbon nanotubes (CCNT) strengthened chitosan (CS) molecularly imprinted polymers (MIPs-CCNT/CS) for non-destructive adsorption of DBT. The introduction of CCNT into CS-based imprinted matrix improved thermal and mechanical stability and enriched adsorption sites of MIPs-CCNT/CS, thus enhancing DBT adsorption ability with the maximum adsorption capacity of 30.58 ± 1.24 mg/g under the optimized adsorption conditions. The Langmuir isotherm and pseudo-second-order kinetics models were verified to fit satisfactorily with the adsorption procedures of MIPs-CCNT/CS towards DBT. Benefiting from the presence of plentiful DBT imprinted cavities, MIPs-CCNT/CS maintained a superior recognition for DBT in the quaternary stimulated diesel, and the relative selectivity coefficients of DBT for benzothiophene (BT), indole, and fluorene with respect to the control non-imprinted adsorbent (NIPs-CCNT/CS) were 2.19, 2.34, and 2.10, respectively. After six adsorption–desorption experiments, the adsorption capacity of MIPs-CCNT/CS toward DBT remained stable (20.67 ± 0.53 mg/g). The preliminary exploration for actual hydrogenated diesel demonstrated that MIPs-CCNT/CS has benign industrial application prospect in the separation and recycling of high value-added DBT.

Density Functional Theory analysis and molecular dynamic simulation to understand the mechanism of hazardous dyes adsorption onto cellulose in aqueous solution

This work examines the use of cellulose in the elimination of anionic dye, indigo carmine and methyl red, from aqueous media. Theoretical analyses revealed that the examined compounds had several reactive sites that encouraged dyes to adhere to the cellulose surface, and molecular dynamics simulations demonstrated that this adsorption occurred flat-lying on the cellulose (200) surface. However, it has been discovered that the reactivity of individual molecules is limited in its ability to foretell the effectiveness and characteristics of compound adsorption on cellulose. The capacity to model dye adsorption on polymeric surfaces in the presence of a simulated aqueous solution is one of the key benefits of molecular dynamics modeling, and it can reveal valuable information regarding the selected molecules' adsorption configuration and its competitiveness. Both dyes exhibit high adsorption on the cellulose adsorbent, indicating that chemical bonds play a major role in the adsorption capacity of the dyes. The order of adsorption energy indicates a clear selective adsorption tendency. The radial distribution function analysis shows that both dyes are chemisorbed at the cellulose surface. Quantum and dynamic descriptors have validated the experimental results in the literature. This offers valuable insights into the adsorption mechanism of anionic dyes on cellulose.

A porous three-dimensional Cu-MOF: Preparation and application in supercapacitors, low temperature hydrogen storage and gas separation

Due to its unique porosity, metal–organic frameworks (MOFs) have great application prospects in the fields of gas adsorption and separation. However, the synthesis of multi-functional MOFs is still a great challenge. Herein, a multi-functional Cu-MOF of {[Cu2(TPTA)(H2O)2]·2DMF·NMP·4H2O}n with a porosity of 62.0 % was designed and synthesized. The H2 adsorption amount of Cu-MOF is about 289.2 cm3 g−1 at 77 K and 1 bar. Meanwhile, the selectivity adsorption of Cu-MOF towards CO2 over CH4 (V:V = 0.5:0.5), CO2/N2 (V:V = 0.5:0.5) and CO2/H2 (V:V = 0.5:0.5) is 95.1, 139.2 and 147.5, respectively, which is 1.5 times higher than the previously reported Cu-MOFs. The Cu-MOF@NF//AC asymmetric supercapacitor demonstrates high specific capacitance (53.4 F g−1) and stability (90.3 % after 2000 cycles). Furthermore, this work presents a novel approach to design multifunctional materials with low temperature hydrogen storage, gas separation and energy storage properties.

Electronic modulation towards MOFs as template derived CoP via engineered heteroatom defect for a highly efficient overall water splitting

The reasonable design of material morphology and eco-friendly electrocatalysts are essential to highly efficient water splitting. It is proposed that a promising strategy effectively regulates the electronic structure of the d‐orbitals of CoP using cerium doping in this paper, thus significantly improving the intrinsic property and conductivity of CoP for water splitting. As a result, the as-synthesize porous Ce-doped CoP micro-polyhedron composite derived from Ce-ZIF-67 as bifunctional electrocatalytic materials exhibits excellent electrocatalytic performance in both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER), overpotentials of about 152 mV for HER at 10 mA cm−2 and about 352 mV for OER at 50 mA cm−2, and especially it shows outstanding long-term stability. Besides, an alkaline electrolyzer, using Ce0.04Co0.96P electrocatalyst as both the anode and cathode, delivers a cell voltage value of 1.55 V at the current density of 10 mA cm−2. The calculation results of the density functional theory (DFT) demonstrate that the introduction of an appropriate amount of Ce into CoP can enhance the conductivity, and can induce the electronic modulation to regulate the selective adsorption of reaction intermediates on catalytic surface and the formation of O* intermediates (CoOOH), which exhibits an excellent electrocatalytic performance. This study provides novel insights into the design of an extraordinary performance water-splitting of the multicomponent electrocatalysts.

Thermally-switchable adsorbent for selective uranium extraction from wastewater

Uranium extraction from uranium-containing wastewater is a promising solution to the uranium resource shortage, but the extraction process faces significant challenges such as poor selectivity, low elution efficiency, and recovery difficulties. In this study, we developed thermally responsive uranium ion-imprinted magnetic mesoporous microspheres (Fe3O4@mSiO2@FIIP) using polymer F-127 as a thermosensitive switch and sodium phytate as a crosslinking monomer, enabling effective uranium recovery from uranium-containing wastewater. By adjusting the adsorption and elution temperatures, Fe3O4@mSiO2@FIIP achieved higher adsorption selectivity and elution efficiency compared to ion-imprinted magnetic mesoporous microspheres without F-127 (Fe3O4@mSiO2@IIP). Additionally, Fe3O4@mSiO2@FIIP demonstrated superior selectivity for uranium ions over other cations compared to non-imprinted magnetic mesoporous microspheres (Fe3O4@mSiO2@NIP). It exhibited excellent salt resistance, reaching adsorption equilibrium within 60 min with a maximum adsorption capacity of 529.5 mg/g. Life cycle assessment (LCA) and techno-economic assessment (TEA) indicated that Fe3O4@mSiO2@FIIP is more environmentally friendly and economically feasible for treating uranium-containing wastewater. This study provides a new paradigm for synthesizing thermosensitive imprinting materials, holding significant potential for uranium recovery applications.

Microscopic adsorption study from coal rank comparison on the feasibility of CO2-rich industrial waste gas injection enhanced coal bed methane recovery

A new method of injecting CO2-rich industrial waste gas (CO2-rich IWG) to displace coal bed methane (CBM) is proposed for energy conservation and green growth. In this study, theadsorption mechanisms of this method were studied by the Giant canonical Monte Carlo and molecular dynamics methods in macromolecular coal models with three ranks (brown, bituminous, and anthracite coal). It is found that the proportion of gas molecules in the adsorbed state is higher in the anthracite coal slit than in the brown and bituminous slits, indicating that anthracite coal seams are more appropriate for waste gas sequestration. The adsorption selectivity of NO and CO2 is consistent among the three coal ranks, with the order of brown > bituminous > anthracite > 1.0, and that of N2 orders as 1.0 > bituminous > anthracite > brown.This is due to the different dominant factors affecting the competitive adsorption between different waste gas components and CBM, namely competition for adsorption sites in the NO and CO2 systems and thefilling effect in the N2 system. There is a positive correlation between the number of major competitive adsorption sites and the adsorption selectivity of theCO2(NO) system. CO2 and CH4 compete for COC structures in brown and bituminous coal and OH structures in anthracite coal, and OH structures in the three coals are the major adsorption sites for NO systems. Our work advances the understanding of the microscopic adsorption mechanisms of CO2-rich IWG in the CBM reservoirs, which provides a theoretical basis for CO2-rich injection-enhanced CBM recovery technology.

Amine-impregnated elastic carbon nanofiber aerogel templated by bacterial cellulose for CO2 adsorption and separation

Carbon aerogel has become a promising electrode material for CO2 capture and capacitor due to its large specific surface area, well-developed pore structure, adjustable porosity and ultra-high specific power. However, most of the carbon-based materials suffer from poor mechanical properties, low recycling efficiency, and low adsorption capacity, making it difficult to be put into industrial applications on a large scale. Bacterial cellulose (BC) has an ultra-fine reticular structure, a modulus of elasticity that is several to more than ten times that of typical plant fibers, and high tensile strength. In this paper, BC was treated by unidirectional freeze-drying method, and the aerogels with ordered honeycomb pore structure were constructed by unidirectional growth of ice crystals, and the pyrolytic chemical properties of BC were adjusted by using (NH4)2SO4, which effectively prevented the shrinkage and deformation of materials during carbonization, and successfully prepared elastic nanocarbon fiber aerogels. At the same time, the introduction of (NH4)2SO4 made the material realize N doping in the carbonization process, providing more adsorption sites, which was conducive to the adsorption of CO2. Finally, the carbon fiber nanoaerogel was modified by TEPA to further improve its adsorption selectivity for CO2. The prepared elastic carbon nanofiber aerogel (CBCNT) has high CO2 adsorption performance and high selectivity, and its CO2 capture capacity is up to 4.88 mmol/g. At the same time, its capacitance also reached 246F/g.

Preparation of highly graphitized porous carbon and its ethane/ethylene separation performance

The efficient separation of ethane (C2H6) and ethylene (C2H4) is crucial for the preparation of polymer-grade C2H4, necessitating the development of highly selective and stable C2H6/C2H4 adsorbents. Highly graphitized porous carbon, denoted GC-800, was synthesized by polymerization at room temperature followed by carbonization at 800 °C using phenolic resin as the precursor and FeCl3 as the iron source. Vienna Ab-initio Simulation Package (VASP) calculations confirmed a higher binding energy between C2H6 molecules and graphitized porous carbon surfaces, so that a high degree of graphitization increased the adsorption capacity of porous carbon for C2H6. However, catalytic graphitization using Fe at high temperatures disrupted the microporous structure of the carbon, thereby reducing its ability to separate C2H6/C2H4. By controlling the carbonization temperature, the degree of graphitization and pore structure of the porous carbon could be changed. Raman spectra and XPS spectra showed that the GC-800 had a high degree of graphitization, with a sp2 C content as high as 73%. Low-temperature N2 physical adsorption measurements estimated the specific surface area of GC-800 to be as high as 574 m2·g−1. At 298 K and 1 bar, it had an equilibrium adsorption capacity of 2.16 mmol·g−1 for C2H6, with the C2H6/C2H4 (1:1 and 1:9, v/v) ideal adsorbed solution theory selectivity respectively reaching 2.4 and 3.8, significantly higher than the values of most reported high-performance C2H6 selective adsorbents. Dynamic breakthrough experiments showed that GC-800 could produce high-purity C2H4 in a single step from a mixture of C2H6 and C2H4. Dynamic cycling tests confirmed its good cyclic stability, and that it could efficiently separate C2H6/C2H4 even under humid conditions.

Design principles for selective nitrogen adsorption via chelation of metals in metal organic frameworks

Designing porous materials with N2 selectivity performance is highly attractive for the efficient removing N2 from natural gas. However, selectively capturing N2 over CH4 is challenging due to their similar physical properties. In this work, we proposed achieving N2 selectivity adsorption over CH4 by chelating Fe2+ sites on the ligands of MOFs. The significant enhancement of N2/CH4 separation by Fe chelation was demonstrated using multiscale simulations, including quantum mechanics calculations, force field development, and GCMC simulations. Specifically, Fe chelated MOFs can achieve a record-high N2 adsorption capacity while maintaining N2/CH4 selectivity comparable to that of current benchmark N2 selective capture MOFs. Moreover, based on simulation data from 331 Fe chelated MOFs with various topologies, we quantified the structure-properties relationships for N2/CH4 separation using Fe chelated MOFs through interpretable machine learning, which provides precise and intuitive guidance for designing novel adsorbents for selective N2 adsorption.

Regulating the Surface State of Carbon Dots as Ultrahigh-Capacity Adsorbents for Water Treatment.

Adsorption is one of the most widely researched and highly effective methods for mitigating the environmental threat posed by recalcitrant dyes in aqueous solutions. This paper presents a solvent-free synthesis method for the rapid and large-scale production of nitrogen (N) and phosphorus (P) co-doped carbon dots (N, P-CDs) which possess specific surface states and outstanding dye adsorption properties. Compared to the undoped CDs, the N, P-CDs not only exhibit a higher yield of solid-state luminescence but also endow them with the efficient adsorption and removal of Congo red (CR) from water. Due to the synergistic effects of π-π stacking, hydrogen bonding and electrostatic attraction, the N, P-CDs exhibit an ultra-high adsorption capacity (3118.87mgg-1) and a removal efficiency (97.4%, at 500mgL-1) for CR, and also display excellent selective adsorption in both single-dye and dual-dye systems. This method offers a rational strategy for synthesizing novel CDs-based adsorbents for CR, which provides a demonstration for future dye adsorption studies and practical wastewater treatment applications of CDs.

Study on highly selective NO2 gas sensors based on (Fe, Mo)-doped monolayer WSe2

The two-dimensional (2D) material WSe2 is frequently employed in gas sensors due to its excellent electrical properties. However, the weak interaction between the pristine WSe2 and gas molecules limits its application. Therefore, in this paper, the adsorption behavior of transition metal X (X = Fe, Mo) atom-doped monolayers WSe2 on H and O atoms and molecules of NO2, HCN, and CO gases is investigated to gain insights into the physical mechanisms of adsorbent-substrate interactions. Doping significantly improves the adsorption properties between the substrate and the gas molecules, with the best adsorption showing for NO2 gas molecules and O atoms. The relationship between transition metals and the improvement of adsorption performance is explored by the center position of transition metal d orbitals in different systems, and it is found that the higher the center position of the transition metal d band, the stronger the adsorption between adsorbent and substrate. Compared to pristine WSe2, Mo atom doping in the transition metal doped system has higher adsorption sensitivity to gas molecules and exhibits highly selective adsorption and chemisorption behaviors through high adsorption energies and electron transfer to NO2 molecules. It is demonstrated that X (X = Fe, Mo) doped WSe2 can be used as a gas-sensitive material for efficient gas detection.

Inverse ceria-nickel catalyst for enhanced C-O bond hydrogenolysis of biomass and polyether.

Regulating interfacial electronic structure of oxide-metal composite catalyst for the selective transformation of biomass or plastic waste into high-value chemicals through specific C-O bond scission is still challenging due to the presence of multiple reducible bonds and low catalytic activity. Herein, we find that the inverse catalyst of 4CeOx/Ni can efficiently transform various lignocellulose derivatives and polyether into the corresponding value-added hydroxyl-containing chemicals with activity enhancement (up to 36.5-fold increase in rate) compared to the conventional metal/oxide supported catalyst. In situ experiments and theoretical calculations reveal the electron-rich interfacial Ce and Ni species are responsible for the selective adsorption of C-O bond and efficient generation of Hδ- species, respectively, which synergistic facilitate cleavage of C-O bond and subsequent hydrogenation. This work advances the fundamental understanding of interfacial electronic interaction over inverse catalyst and provides a promising catalyst design strategy for efficient transformation of C-O bond.

High‐Efficiency Separation of Near‐Zigzag Single‐Chirality Carbon Nanotubes by Gel Chromatography

High‐efficiency production of near‐zigzag single‐chirality single‐wall carbon nanotubes (SWCNTs) is of great importance for their property study and applications. The key to separate near‐zigzag single‐chirality SWCNTs by gel chromatography is to selectively adsorb them in the gel medium. In this study, by using a high surfactant ratio of sodium dodecyl sulfate and sodium cholate (≥4:1) to modulate the selective adsorption of distinct (n, m) SWCNTs in a gel column, a high enrichment of near‐zigzag SWCNTs adsorbed in the gel column is achieved, which usually have a low abundance in raw materials due to their low growth efficiency. Afterward, (7, 3), (8, 3), (8, 4), (9, 1), and (9, 2) single‐chirality SWCNTs are separated with small chiral angles less than 17° by following a stepwise elution for their selective desorption. This simple and efficient separation technique will promote the research and application of near‐zigzag SWCNTs.