Small Mesopores Research Articles

Tailoring Multiple Porosities of Hierarchical ZSM‐5 Zeolites by Carbon Dots for High‐Performance Catalytic Transformation

AbstractA simple and high‐efficiency method is proposed to synthesize hierarchical ZSM‐5 zeolites with micropore and multistage mesopores by adopting water‐soluble carbon dots (CDots) with various size distributions, such as 1‐stage size distribution of CDots‐1 of around 23 nm, 2‐stage size distribution of CDots‐2 of 6 and 9 nm, 3‐stage size distribution of CDots‐3 of 5, 8, and 18 nm. The abundant OH and COOH groups on the surface of CDots provide high solubility in water. The characterization techniques confirmed that the dual‐porous h‐ZSM‐5 (MIcro–mEsopores) and multi‐porous h‐ZSM‐5 (MIcro–mEso–mEsopores), h‐ZSM‐5 (MIcro–mEso–mEso–mEsopores, M‐IEEE) catalysts are obtained. Notably, the hierarchical ZSM‐5(M‐IEEE) catalyst with micropore of 0.55 nm, two small mesopores of 4.8 and 7.4 nm, and one large mesopore of 17.5 nm show excellent catalytic performance with the highest 1,3,5‐triisopropylbenzene (TIPB) cracking conversion (97.3%) and high stability. Similarly, the h‐ZSM‐5(M‐IEEE) shows the high ethanol to olefins conversion (100%). The improved catalytic activity can be attributed to the more efficient diffusion of reactants and products in the crystals with the help of multistage mesopores, improved anti‐coking stability, combined with the effect of suitable acidity, and the increased accessibility of the acid sites.

Rapid synthesis of dual-mesoporous silica aerogel with excellent adsorption capacity and ultra-low thermal conductivity

In this paper, using methyltriethoxysilane (MTES) and tetraethoxysilane (TEOS) as co-precursor, dual-mesoporous silica aerogel was rapidly prepared within 20 h by ambient pressure drying. The dual-mesoporous structure can be obtained just by control the amount of TEOS. The skeleton structure of the dual-mesoporous aerogel is composed of small mesopores (3-6 nm) and large mesopores (17-30 nm). Moreover, the thermal conductivity (as low as 0.0223 W/(mK)) of the dual-mesoporous aerogel is much lower than most of MTES-based aerogels. More importantly, the obtained dual-mesoporous aerogel can separate oil from surfactant-stabilized oil-in-water emulsion, the separation efficiency as high as 97.6%. In addition, the aerogel exhibits superhydrophobic with a contact angle of 157.4°, thermally stable reaching up to 489.5°C and outstanding sorption capacity reaching up to 8.4-17.1 g/g. The dual-mesoporous silica aerogel have potential application in thermal insulating and organic pollutants sorption.

Theoretical performance of multiple size-exclusion chromatography columns connected in series

The fundamental relationships are derived for the retention, peak width, and peak capacity of non-retained polymers eluting from multiple standard size-exclusion chromatography (SEC) columns connected in series. The standard SEC columns may have different dimensions and are packed with particles having distinct average particle diameters (APDs) and average mesopore sizes (AMSs). The performances (peak capacity, local resolution power, and sensitivity) of three standard SEC columns connected in series (called a tri-SEC column) packed with bridged-ethylene-hybrid (BEH) fully porous particles (FPPs) having three different APDs (1.7, 2.5, and 3.5 μm) and AMSs (200, 450, and 900 Å, respectively) are calculated as a function of the applied flow rate and size of polystyrene standards. Irrespective of the APD and AMS, the present investigation assumes isomorphological materials relative to the mesopore space of the three different BEH particles. The advantage of a 15 cm long tri-SEC column over a single reference SEC column (APD=3.5 μm, AMS=900 Å), which generates the same back pressure and separation window as those of the tri-SEC column, is expected at flow rates larger than the optimum flow rate generating the maximum peak capacity. The calculations predict a significant relative increase of the peak capacity (from +25% to +85%), resolution of small molecules (from +75% to +225%), and of the detection limit of intermediate size (from +15% to +70%) and largest polymers (from +25 to +110%). This is explained by 1) the exclusion of the largest polymers from the internal volume of the particles having the smallest mesopores (restricted access media) and 2) the minimum dispersion along the columns packed with the smallest particle sizes in the tri-SEC column. The main benefit of multi-SEC columns is to easily adjust the desired pore size distribution by properly selecting the lengths of each individual SEC column. The user can then control the pore size distribution for any specific separation problem. A potential application is theoretically demonstrated for the fast purification of monoclonal antibodies from metabolites, host cell proteins, aggregated forms, and from virus-like particles.

Evaluation of surface diffusion in microporous/mesoporous media using a numerical model applied to rate-of-adsorption data: Implications for improved gas permeability estimation in shales/tight rocks using drill cuttings

Adsorbed-phase surface diffusion has been recognized as an important controlling factor on gas apparent permeability in micropores and smaller mesopores. However, for the estimation of surface diffusion coefficients of shales, the commonly used empirical methods cannot account for the complexity of rock fabric in the matrix system of tight rocks. Further, the small sample sizes and amounts (<5 g) of drill cuttings, which are usually the only reservoir samples available from horizontal wells, significantly limit the feasibility and reliability of current experimental methods for the direct quantification of surface diffusion coefficients. The primary objectives of this study are therefore to: 1) establish an integrated experimental and modeling approach to evaluate surface diffusion and permeability using drill cuttings, and 2) investigate the significance of surface diffusion in different adsorbate/adsorbent systems. In this work, a bidisperse numerical model is developed to extract surface diffusion coefficients and permeability/diffusivity values from porous materials by matching the pressure transient data recorded during gas adsorption. A high-resolution gas adsorption apparatus is employed to measure gas sorption kinetics under low-temperature (N2, −196 °C; CO2, 0 °C), low-pressure (<0.1 MPa) conditions, using small amounts (<2 g) of powdered/crushed samples. The proposed model successfully matched rate-of-adsorption (ROA) pressure transient data on two synthetic micro/mesoporous materials (Activated Carbon and SBA-15) and five organic-rich shale samples. It was observed that surface diffusion is a dominant flow mechanism and enhances permeability/diffusivity in micropores and smaller mesopores. The new model improves upon the results of a previously-developed ROA model.

Hydrothermal Activation of Porous Nitrogen-Doped Carbon Materials for Electrochemical Capacitors and Sodium-Ion Batteries.

Highly porous nitrogen-doped carbon nanomaterials have distinct advantages in energy storage and conversion technologies. In the present work, hydrothermal treatments in water or ammonia solution were used for modification of mesoporous nitrogen-doped graphitic carbon, synthesized by deposition of acetonitrile vapors on the pyrolysis products of calcium tartrate. Morphology, composition, and textural characteristics of the original and activated materials were studied by transmission electron microscopy, X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy, infrared spectroscopy, and nitrogen gas adsorption method. Both treatments resulted in a slight increase in specific surface area and volume of micropores and small mesopores due to the etching of carbon surface. Compared to the solely aqueous medium, activation with ammonia led to stronger destruction of the graphitic shells, the formation of larger micropores (1.4 nm vs. 0.6 nm), a higher concentration of carbonyl groups, and the addition of nitrogen-containing groups. The tests of nitrogen-doped carbon materials as electrodes in 1M H2SO4 electrolyte and sodium-ion batteries showed improvement of electrochemical performance after hydrothermal treatments especially when ammonia was used. The activation method developed in this work is hopeful to open up a new route of designing porous nitrogen-doped carbon materials for electrochemical applications.

Nb2O5/SiO2 monoliths with tailored porosity: the role of polyethylene glycol as pore modulating agent

The role of polyethylene glycol (PEG) as pore modulating agent was studied in the preparation of monoliths formed by Nb2O5 nanoparticles dispersed in a silica matrix obtained by the sol–gel process. The obtained monoliths were characterized by gas adsorption, SEM and HRTEM (EELS coupled). The silica and nanocomposite monoliths showed high specific surface area and pore size varying between micro and macropores, depending on the amount of PEG used. The silica monoliths were transparent due to the micro and small mesopores, the nanocomposites with 1 and 5% of PEG were translucid and the nanocomposite with 3% of PEG were opaque due to spinodal decomposition induced by the interaction between the polymer and the niobium pentoxide precursor (ammonium niobate oxalate hydrate), which made it a promising candidate for flow catalysis or chromatographic columns.

A Novel Anthraquinone‐Containing Poly(Triphenylamine) Derivative: Preparation and Electrochemical Performance as Cathode for Lithium‐Ion Batteries

AbstractOrganic and polymeric materials are excellent candidates for next generation advanced electrode materials. Therein, 2,6‐Bis(4‐(diphenylamino)phenyl)‐9,10‐anthracenedione (BDAPA) functional monomer was synthesized through Suzuki coupling reaction, and a novel anthraquinone‐containing poly(triphemylamine) polymer (PBDAPA) was then prepared by the simple oxidative polymerization. The obtained novel functional polymer presented a unique urchin‐like morphology with outgrowth of hollow tubular spiny, which possesses the improved specific surface area of ∼129.6 m2 g−1 and the small average mesopore diameter of 1.78 nm. As cathode material, the obtained PBDAPA compared to polytriphenylamine (PTPA), demonstrated two obvious discharge plateaus, corresponding to the double charge‐discharge characteristics from p‐type triphenylamine and n‐type anthraquinone segments in the polymer, respectively. Also, PBDAPA exhibited an improved specific capacity of 132.7 mAh g−1 and an enhanced rate capability with the discharge specific capacities of 140.6, 124.3, 107.5 and 97.1 mAh g−1 at the discharge rates of 20, 50, 100 and 200 mA g−1, respectively. The introduction of anthraquinone unit in polytriphenylamine as well as the resulted open pore morphology for PBDAPA was responsible to the improved electrochemical performances, which makes it a potential strategy for the design and preparation of high performance organic lithium‐ion batteries.

Hierarchically porous carbon derived from potassium-citrate-loaded poplar catkin for high performance supercapacitors

A simple one-step preparation of biomass derived carbon materials with hierarchical pore structure for supercapacitor application is proposed. Briefly, potassium citrate is loaded onto poplar catkin, a forestry and agricultural residue, for carbonization at different temperature (750–900 ℃). With the confined effect of poplar catkin and pore-forming role of potassium compounds, interconnected carbon networks combining of macropores, small mesopores and micropores are obtained. The product carbonized at 850 ℃ (S-850) processes large surface area of 2186 m2/g with two main micropore ranges distributed in 0.5–0.7 nm and 0.7–1.5 nm, and the sample of S-900 processes relatively high electrical conductivity because of the high degree of graphitization. The electrodes based on these carbon materials show main electrical double-layer capacitors with small part of pseudo-capacitors due to O-doping. The S-850 sample displays superior specific capacity at low charge–discharge current density while the electrode based on S-900 shows high specific capacity under high current density. The symmetrical devices based on S-850 give a superb stability and high energy and power densities in alkaline electrolyte. Within a voltage window of 1.4 V, the device can deliver a 13.3 Wh/kg energy density at a power density of 720 W/kg and maintain 7.8 Wh/kg at 14040 W/kg.

Study on co-adsorption mechanisms of benzene and toluene on activated carbon via molecular simulation

In this paper, four-type activated carbon (AC) models are constructed and the co-adsorption processes of benzene and toluene on models under 303.15 K are studied by molecular simulation. The microscopic mechanisms in adsorption process including isotherms, energy changes, adsorption sites, and diffusion coefficients were discussed. The results indicate the small micropores less than 13 Å and larger micropores, smaller mesopores from 13 Å to 24 Å are favorable for benzene adsorption and toluene adsorption, respectively. Moreover, the adsorption amounts increase with the increase of oxidation degree in AC structure.

Diffusion in hierarchical silica monoliths: impact of pore size and probe molecule

The silica monoliths were prepared by a combination of sol-gel synthesis, pore templating, and a process of phase separation. The as-prepared monoliths are characterized by meso- and macroporosity. The pore size significantly differs for each sample depending on the preparation conditions. The transport properties of the monoliths were investigated using benzene, isopropanol, hexane, and methane as probing molecules. The effective diffusion coefficients in the monoliths were estimated based on the second Fick’s law of diffusion. The obtained diffusivities are quite similar for different samples, demonstrating that the diffusion occurs mainly in the macropores of the monolith. The values of the diffusion coefficients were found to fall outside the Knudsen prediction. In addition, it was investigated that the benzene and hexane transport in the monolith sample with a bimodal mesopores distribution does not follow the Fick’s diffusion law. To describe the mass transfer of the benzene and hexane in this sample the time-fractional diffusion equation was utilized on a phenomenological basis. Several scenarios concerning the role of the relatively small mesopores in the hydrocarbons diffusion are discussed.

A comparison of nano-scale pore attributes of Barakar Formation gas shales from Raniganj and Wardha Basin, India using low pressure sorption and FEG-SEM analysis

This study investigates the micropore-mesopore spectrum in gas shales by augmenting two different pore size distribution calculation methods using two probe gases in low-pressure sorption analysis. The Barakar Formation shale samples collected from Wardha and Asansol belonging to two key potential basins in India, namely Wardha and Raniganj, were studied to identify possible variations in pore attributes in shales, and a comparison was drawn. A combination of CO2 and N2 low-pressure gas adsorption studies was implemented to resolve micro- and meso-pores, using the respective probe adsorbate. The visual representation of the pore structure and its disposition was facilitated by high-resolution microscopic imaging, and aided by image analysis. The results show a positive correlation between clay mineral composition and the mesopore attributes as well as organic matter composition and micropore attributes. This confirms that both inorganic and organic content of shales contains large pore volumes, albeit in different pore dimension ranges with some overlap. High N2 adsorption potential of Asansol shale, as well as high CO2 adsorption potential of Wardha valley shale, is conformable with their respective pore size distributions. Fractal characteristics of mesopores suggest that the larger mesopores have a rougher surface, whereas the smaller mesopores have a smoother surface (with average fractal dimensions of 2.6 and 2.2, respectively). Although all examined shales belong to the same geological formation, they exhibit distinctly variable pore attributes and gas storage potential.

Multistage Self-Assembly Strategy: Designed Synthesis of N-doped Mesoporous Carbon with High and Controllable Pyridine N Content for Ultrahigh Surface-Area-Normalized Capacitance

Nitrogen doping could improve the performance of carbon materials in electrocatalysis, CO2 adsorption, and energy storage. [1]However, the control of the doping type and the amount of nitrogen (N)-...

Small mesopore engineering of pitch-based porous carbons toward enhanced supercapacitor performance

The advancement of modern carbon-based supercapacitor depends strongly on the porous carbons (PCs) with tailoring pore configuration. To achieve the trade-off between power density and energy density, enriching small mesopore in PCs is an important but challenging research subject. Herein, the PCs with customizable small mesopores were fabricated from cheap coal tar pitch (CTP) by adjusting their content of light component (i.e. toluene soluble CTP, TS). The share of small mesopore in total pore structure of PCs (V2–4 nm/Vtotal) progressively increases with the lifting TS content of precursor. Consequently, the specific surface area and pore volume of PCs increase first and then decrease as the TS content increases. Simultaneously, the influence of small mesopore on the capacitance performances of supercapacitors was reflected in their capacitance, rate capability, cycle stability and self-discharge performance. The supercapacitor assembled by the PC with a V2–4 nm/Vtotal of ~31.3% delivers a superior energy density of 0.15 mW h cm−2 at a power density of 5.40 mW cm−2. Therefore, the small mesopore engineering in carbon materials derived from inexpensive precursors broadens the avenue to further improve the areal capacitive performance of supercapacitors by a facile up-scalable approach.

Development of mesoporous ZSM-5 zeolite with microporosity preservation through induced desilication

Alkali treatment is a widely used strategy to create mesopores for microporous zeolites to decrease the diffusion limitation in micropores. However, many of the micropore losses existed due to the uncontrollable destruction of framework. In this paper, a series of mesoporous ZSM-5 with well-maintained micropores was synthesized through induced desilication strategy. To induce the diffusion of alkali solution for the homogenizing desilication and mesopore formation, abundant and uniform small mesopores were firstly built for ZSM-5 by protective desilication in tetrapropylammonium hydroxide solution. The pore structure and acidity of the obtained ZSM-5 were characterized by XRD, TEM, N2 physisorption, NH3-TPD and Py-IR. Through induced desilication, the external surface area of obtained ZSM-5 increased from 42 m2 g−1 of parent ZSM-5 to 148 m2 g−1 and only 17% of micropore surface area was sacrificed, which was far lower than 37% of the loss in traditional NaOH treatment. Meanwhile, the strong acid sites were well preserved and the external acid sites were reduced. Compared with the sample treated by NaOH solution, the obtained catalyst exhibited higher catalytic stability and aromatics, especially PX selectivity. Good regenerated performance with long catalytic lifetime and high liquid hydrocarbon yield could also be found for the obtained catalyst. The strategy proposed in this paper is simple and ingenious in tailoring the porosity since it only relies on the desilication method, which is different from the usual coupling of dealumination and desilication.

Loofah Sponge-Derived Sulfur-Rich Porous Carbon with Micropores and Small Mesopores as High Performance Anode Material for Lithium Ion Batteries

Loofah Sponge-Derived Sulfur-Rich Porous Carbon with Micropores and Small Mesopores as High Performance Anode Material for Lithium Ion Batteries

Block Copolymer‐Directed Synthesis of Conjugated Polyimine Nanospheres with Multichambered Mesopores

AbstractConjugated polyimines constructed from aromatic amines and aromatic aldehydes have attracted enormous attention because of their excellent and fascinating properties. However, the structure of these materials constructed by building blocks or linkers is usually confined to a scope of microporosity and small mesopores (less than 5 nm), which largely impedes their applications in many fields. Here, a facile self‐assembly strategy is developed to controllably fabricate conjugated polyimines nanospheres with multichambered mesoporous architecture by using polystyrene‐b‐poly(acrylic acid) diblock copolymer as a soft template. Given the wide availability of amines and aldehydes, it is expected to open new avenues for designing diverse polyimine‐based materials with controlled mesostructure toward applications.

Ultraviolet-Induced Interfacial Crystallization of Uniform Nanoporous Biphasic TiO2 Spheres for Durable Lithium-Ion Battery

Porous TiO2 has been widely studied as an anode material of lithium-ion battery, most of which, however, are crystalline with a limited surface area (e.g., 50–120 m2/g) and a large pore size of 10–20 nm greatly exceeding the ion radium of Li+ ion and its complexes. Herein a facile UV-induced interfacial crystallization method is developed for the sol–gel-derived amorphous hydrous TiO2 spheres (HTS) at ambient condition. Tuning the dispersant (e.g., ethanol, H2O, methanol, or their mixture) and the wavelength of the light source allows for selective control over the crystal phase of anatase, rutile, or their biphase formed at the spherical surface, although the total crystallinity remains poor. The optimal nanoporous biphasic TiO2 spheres of anatase and rutile upon 254 nm UVC irradiation of HTS in H2O and methanol mixed solution for 4 h exhibit an ultralarge surface area of 358.1 m2/g and comprise numerous micropores and small mesopores (∼3.31 nm), rendering the fabricated LIB with high current density, rate capacity, cycle performance, and Li+ transfer rate. A superior electrochemical reversible specific capacity of 128.6 mAh/g can be attained over 1000 cycles of charge/discharge processes at 1C rate. Our simple and general synthesis strategy is promising for the rational design of various photostable materials with improved crystallinity, tunable crystal phases, large surface area, and applicable pore size.

Revealing Structure–Activity Links in Hydrazine Oxidation: Doping and Nanostructure in Carbide–Carbon Electrocatalysts

The oxidation of hydrazine (N2H4) is an important challenge in electrocatalysis, with applications in direct hydrazine fuel cells and in medical and environmental sensing. Interest in alternative, nitrogen-based fuels for fuel cells was rekindled by recent advances in alkaline membranes, and by the surfacing of challenges in the transportation of hydrogen. Direct hydrazine fuel cells promise high theoretical voltage (1.56 V with O2), clean emissions, and improved fuel transportability.We now report a multi-doped carbide–carbon composite with excellent hydrazine electro-oxidation (HzOR) activity in alkaline pH. While iron carbide containing materials are well known catalysts for several applications (e.g. oxygen reduction and Li-ion batteries), our N-doped, Fe3C-embedded carbons provide the first examples of a carbide-based HzOR catalyst. Multi-doping was thought to enhance reactivity (possibly through cooperation of M=Cu/ Zn, Fe, and edge N atoms), possibly by pore-etching, layers exfoliation or graphitization promotion, thus modulating surface area, mass transfer and conductivity.To prepare the composites, we designed tunable multi-doped precursors: an organometallic structure combining iron with either (1) copper, an element active towards the HzOR, (2) zinc, an electrocatalytically-inert element capable of efficient micropore etching, or (3) iron, to investigate the effect of molybdenum-doping reported earlier. Pyrolysis and washing of the fore mentioned precursors yielded HzOR-active composites of Fe3C nanoparticles and a hierarchically porous, partially graphitic N-doped carbon (NC). Thorough characterization by voltammetry and by a broad range of spectroscopic and microscopic methods revealed that the activity is ordered as: Cu-derived NC > Zn-derived NC > Fe-derived NC. While the catalysts had similar compositions, their nanostructure varied: both Zn- and Cu-doping induced the formation of micropores and small mesopores (5–13 nm diameter). The dopant-induced active site exposure (affecting micropore volume) and improved material flow (linked to mesopore volume) contributed to enhanced HzOR electroactivity. Furthermore, the intimate mixing of the metals in the precursor is hypothesized to homogenize and enhance the doping effect, as the structure enhancing metal ions (Zn2+ or Cu2+) exposed the nearby catalytic Fe3C sites. Acid washing of the pyrolyzed carbon was crucial for producing microporosity in the Cu-based carbon, but had little effect on the Zn-derived one. This revealed the importance of micropores and small mesopores for HzOR electrocatalysis, and the different nanostructuring mechanisms of the two dopants: while Zn(g) boils during pyrolysis and thus etches micropores into the carbon, Cu(s) diffuses and spreads throughout, making exfoliation by acid reaction more efficient. Further work in our group is dedicated to the catalytic activity of pure phase Fe3C, and its modification by other dopants.[Burshtein et al., J. Mater. Chem. A, 2019, doi: 10.1039/C9TA03357B] Figure 1

Nanoestructuras de sílice, con diámetro y distribución de mesoporos variable, modificadas con ácido tungstofosfórico como catalizadores en la síntesis de quinoxalinas

Se sintetizaron catalizadores (SNX#WPA) basados en ácido tungstofosfórico, en soportes de nanoestructuras de sílice (SNX), con distribución de diámetros y tamaños de mesoporos variables. Las SNX se prepararon en medio de octano/agua, usando poliestireno y bromuro de cetiltrimetilamonio como plantillas. Los materiales se caracterizaron por DRX, TEM y adsorción/desorción de nitrógeno. La relación octano/agua influyó tanto en la morfología y el tamaño de las SNX como en la distribución del tamaño de poro. Las SNX obtenidas utilizando relaciones OCT/H2O en el rango de 0,07-0,35, presentan mesoporos pequeños (5-6 nm) y grandes (28-34 nm), generados principalmente por poliestireno. Los mesoporos grandes y su contribución de volumen fueron claramente más altos que en las muestras SN1, SN2 y SN3. La estructura y la morfología de SNX#WPA fueron similares a las de las SNX usadas como soporte. Además, la caracterización de todos los materiales SNX#WPA por FT-IR y 31P NMR indicó la presencia de especies [PW12O40]3− y [H3-XPW12O40](3-X)− sin degradar. Según los resultados de la valoración potenciométrica, los sólidos presentaron sitios ácidos muy fuertes. Se evaluó la actividad de SNX#WPA como catalizadores en la síntesis de quinoxalinas, a partir de lo cual se obtuvieron altos rendimientos, sin formación de subproductos. De ello resultó que los materiales preparados son catalizadores altamente selectivos y reutilizables.

Analysis of equilibrium and dynamic adsorption of benzene vapor over unimodal and bimodal silica-based mixed-metal oxides

In this study, purification of a benzene-lean gas stream over unimodal and bimodal silica-based mixed-metal oxides was investigated for the purpose of understanding the effects of secondary metal oxide and support pore structure on the adsorption capacities and kinetics. The unimodal silica fell in the borderline of micropores and mesopores, i.e., they consisted of large micropores and small mesopores with large surface area, while the bimodal silica consisted of large micropores, small mesopores and large mesopores with large mesopore volume. The titania and zirconia mixed-metal oxides showed reduced surface area and pore volume as a result of partial blockage of the pores, however, they exhibited improved adsorption behavior relative to the bare silica. Equilibrium adsorption measurements revealed unimodal adsorbents are superior to their bimodal analogues by exhibiting higher benzene vapor uptake, with capacities reaching 10.05, 11.71 and 11.25 mmol/g for SiO2, TiO2/SiO2 and ZrO2/SiO2 samples at 25 °C and 101 kPa. In contrast, dynamic breakthrough tests with 465 ppm benzene vapor concentration indicated faster adsorption kinetics for bimodal adsorbents relative to unimodal materials as a result of their larger pores which produced lesser intraparticle diffusion resistance. It was also found that, while titania or zirconia incorporation enhances the equilibrium adsorption capacity of the bare silica, it deteriorates the adsorption rate. Similarly, all the adsorbents depicted partition coefficient in the range of 0.31–1.75 mmol/g/μM. The mass transfer coefficients estimated from concentration profiles of bimodal SiO2, TiO2/SiO2 and ZrO2/SiO2 samples were 0.58 and 0.45, and 0.41 s−1, respectively. Overall, the findings of this investigation indicated that the introduction of large mesopores in the structure of microporous-mesoporous silica is a facile approach in developing mixed-metal oxide adsorbents with improved adsorption capacity and kinetics for the abatement of benzene vapor emissions.