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Crystal engineering of hierarchical zeolites is regarded as a promising way to enhance diffusion-dependent catalytic properties of zeolitic materials. Crystallization process control on crystal size and pore-structure is desirable over porogen based protocols and post-synthetic methods for the low cost, high yield and potential scalability. Herein, a tumbling crystallization of hierarchical ZSM-5 zeolite in immiscible water/toluene Pickering emulsion inspired by energy dissipating structure occurring in nature is presented. The structure and acid properties of the obtained hierarchical material have been revealed using a panoply of characterization techniques such as powder X-ray diffraction, N2 physisorption isotherms, SEM, TEM, mercury protrusion measurements, NH3-TPD and pyridine IR spectroscopy, showing that the material contains high crystallinity, and penetrating macropores. Crystallization is found to proceed through a Pickering emulsion structure maintained by emulsifying effect of constant tumbling. Such an emulsion structure has hindered attachment growth of primary nanocrystals formed at the nucleation stage to further grow into larger size via coalescense. The hierarchical zeolite exhibits architecture-dependent prolonged catalyst lifetime and light olefin yield in dimethylether-to-olefin conversion. This process control to generate hierarchical zeolites opens up new ways toward inexpensive, high level control and efficient engineering of zeolite morphology.

Generation of hierarchical zeolites is an effective way to enhance their diffusion-dependent catalytic properties. The fabrication of hierarchical zeolites with enhanced diffusion property, high hydrothermal stability, strong acidity in an inexpensive, facile and efficient way is particularly daunting. Here, a simple synthesis of hierarchical SSZ-13 zeolite in a biphasic water/toluene media under tumbling assisted by organosilane, i.e., trimethoxy[3-(phenylamino)propyl]silane, is proposed. The obtained material with tunable Si/Al from 10 to 30 consists of assembled crystallites of 20–30 nm that construct a hierarchical architecture with mesopores of ca. 7 nm opening to the external facets, and has low defect concentration and preserved strong acidity. Crystallization mechanism is disclosed to obey a non-classic attachment growth of nano building blocks mediated by Pickering emulsion, as organosilane modification changes their surface to be hydrophobic. Such a crystallization pathway has accelerated nucleation process and suppressed the growth of SSZ-13 crystals to micron size. Cu exchanged hierarchical SSZ-13 outperforms the standard sample in typical NH3-SCR process in both low and high temperature regimes as a result of enhanced diffusion property, as well as low defect concentrations. The synthesis is a cost-effective method for the generation of hierarchical zeolites mediated by the presence of a liquid/liquid interface, and could inspire more such explorations.

We present a phase-transfer crystallization approach to the synthesis of ultrasmall (

Controlling crystal size and shape of zeolitic materials is an effective way to promote their mass transport and catalytic properties. Herein, we report a single step, Na+ - and porogen- free crystallization of MFI hierarchical architecture made up of aligned nanocrystals with reduced b-axis thickness (5-23 nm) and adjustable Si/Al ratios between 35 to 120, employing the commonly used tetrapropylammonium hydroxide (TPAOH) and tetrabutylammonium hydroxide (TBAOH) as structure-directing agents (SDAs). Homogeneous nucleation driven by both SDAs and subsequent SDA-exchange induced dissolution-recrystallization are responsible for the formation of such structure. The enhanced textural and diffusion properties account for a notable exaggeration of propene selectivity and catalyst lifetime in dimethyl ether-to-olefins (DTO) conversion. This protocol is extendable to the rational synthesis of other hierarchical zeolites through crystallization process control.

The catalytic performance of silicoaluminophosphates is dependent on their acidity and diffusion properties, which can be altered by an organic structure-directing agent (OSDA) as a result of its dominant effect on crystallization. Generally, the solubility of an amine in aqueous media is an important factor for judging whether it is suitable to serve as an OSDA in hydrothermal synthesis of zeolites. This work demonstrates that a hydrophobic molecule, tri-n-heptylamine, could be used as an OSDA for synthesis of hierarchically porous SAPO-31 in biphasic toluene/water media. It provides not only a new method for synthesis of zeolites but also a simple, inexpensive, and porogen-free pathway to generate hierarchical SAPOs. The synthesis allows manipulation of the nSi/(nAl + nP + nSi) ratio from 0.02 to 0.13 without noticeable change of morphological features. The self-assembled, nanocrystalline structure was revealed by combined XRD, SEM/TEM, N2 physisorption, and 27Al, 31P and 29Si MAS NMR spectroscopy, and the acidity was measured with NH3-IR. Catalytic evaluation in n-dodecane hydroisomerization shows that the isomer yield depends on the acid site density of the catalysts, and weak acid strength and high acid site density should be avoided to achieve high selectivity. On the optimized catalyst, the isomer yield has been significantly improved up to 79.7% in contrast to 58.1% for the sample derived from usual hydrothermal synthesis with di-n-hexylamine as an OSDA.

The SUZ-4 zeolite membrane was prepared on the hollow fiber ceramic membrane via the secondary growth method modified by the dynamic hydrothermal process. The surface morphology and pervaporation (PV) performance of zeolite membranes fabricated by dynamic and static hydrothermal processes were studied. The surface of the zeolite membrane prepared by the dynamic hydrothermal process was covered with rod-shaped crystals, while the static one was full of crystal clusters fabricated by small-sized crystals. Besides, the separation factor of the SUZ-4 zeolite membrane made via dynamic hydrothermal method for separating 10 wt% methanol (MeOH)/methyl methacrylate (MMA) mixture at 50 °C exceed 10000 with a flux of 3.83 kg·m−2·h−1, which was better than the static one and showed excellent long-term stability. This work provided the important assistance for the preparation of SUZ-4 zeolite membranes in the separation of MeOH/MMA and MeOH/dimethyl carbonate (DMC) organic mixtures and demonstrated the great potential of dynamic process in promoting the membrane properties.

Changing size and shape of zeolitic crystals brings about enhanced diffusion properties and related promotion of catalytic performances. This work puts forward a phase-transfer synthetic strategy to generate ATO nanocrystalline silicoaluminophosphates spheroids under tumbling crystallization using aluminum isopropoxide dissolved in toluene and other ingredients (fumed silica/phosphoric acid/Di-n-hexylamine) dissolved in water as precursors. Toluene and aqueous phase formed a Pickering emulsion like structure during hydrothermal crystallization. Highly uniform crystalline spheroids of weighted 55 nm with strong acidity and high surface area were obtained, which exhibited a high isomer yield up to 79% in n-heptane hydroisomerization. Comparisons of product distribution and kinetic studies suggest that monomethylbranched isomer selectivity is controlled by product shape selectivity, whereas dimethylbranched isomer selectivity is affected by combined transition state and product shape selectivity. The increase in selectivity for ATO spheroids is attributed to an expansion of intrinsic reaction controlled temperature regime and an improved diffusion property.

Nanosized SAPO-34 has been successfully synthesized by a facile and low-cost method involving an azeotrope evaporation and steam-assisted crystallization route without either expensive poregens or homemade starting materials. The as-synthesized nanosized SAPO-34 shows ultrasmall grain sizes and an impressively high total pore volume, as confirmed by X-ray diffraction, nitrogen physisorption, scanning electron microscopy, and transmission electron microscopy techniques. The formation process and the pivotal role of supersaturation in the synthesis of nanosized SAPO-34 have been revealed by a series of control experiments, on the basis of which a nonclassic oriented attachment mechanism under high supersaturation ratio conditions is proposed. When used as the catalyst for the conversion of chloromethane to olefins, the nanosized SAPO-34 exhibits acidity comparable to that of the conventional SAPO-34 but double the catalytic lifetime and a slightly lower selectivity for light olefins.

Currently, the application of supercapacitors (SCs) in portable electronic devices and vehicles is limited by their low energy density. Developing high-energy density SCs without sacrificing their advantages, such as their long-term stability and high power density, has thus become an increasing demand but a major challenge. This demand has motivated tremendous efforts, especially towards discovering and optimizing the architecture of novel electrode materials. To this end, we herein report the design, synthesis, and SC application of a new family of two-dimensional (2D) nanoplatelets, i.e., a transition-metal hydroxymethylate complex (Ni x Co1–x (OH)(OCH3)). Bimetallic nanoplatelets were synthesized via a cost-effective approach involving a one-step solvothermal procedure. We for the first time tuned the metal composition of these 2D nanoplatelets over the entire molar-fraction range (0–1.0). Tuning the molar ratio of Ni/Co allowed us to optimize the structures and physicochemical properties of the nanoplatelets for SC applications. When tested in a half cell, SC electrodes using the nanoplatelets exhibited high electrochemical performance with a specific capacitance as high as 1,415 F·g–1 and a 96.1% retention of the initial capacitance over 5,000 cycles. We exploited the novel 2D nanoplatelets as cathode materials to assemble a hybrid SC for full-cell tests. The resulting SCs operated in a wide potential window of 0–1.7 V, exhibited a high energy density over 50 Wh·kg–1, and sustained their performance over 10,000 charge–discharge cycles. The results suggest that the novel 2D nanoplatelets are promising alternative materials for the development of high-energy density SCs.

Transforming natural kaolin into pure-phase hierarchical aggregates of nano ZSM-11 has been achieved by using a novel tetrabutylphosphonium hydroxide as a structure-directing agent via steam-assisted crystallization. The hierarchical ZSM-11 possesses a small particle size (about 240 nm), large surface area (428 m2 g−1), and abundant mesopores (0.30 cm3 g−1). Moreover, the hierarchical ZSM-11 exhibits prolonged catalytic lifetime and promoted aromatic selectivity in the methanol-to-aromatics reaction. The superior catalyst stability is attributed to the better capacity of accommodating the coke and a lowered coking rate.

Phenyltrimethoxysilane as a Si source can significantly slow down the crystallization process for SAPO-34 synthesis, leading to the formation of agglomerated nanocrystals (

Understanding silicoaluminophosphate formation mechanism lays the foundation for their structure manipulation via crystallization process control. Crystallization of SAPO-34 from a dry gel using tetraethyl ammonium hydroxide as structure-directing agent was monitored to unravel the formation mechanism. The initial gel was found to form a lamellar precursor first, which subsequently underwent phase transformation to discrete SAPO-34 nanocrystallites. The nanocrystallites thereafter mutually aligned with neighboring ones via a non-classic oriented attachment growth mechanism, affording large crystals as a result of grain boundary elimination. A new protocol to prepare hierarchical SAPO-34 was designed by hindering the aggregation of primary nanocrystallites with a growth inhibitor 1,2,3-hexanetriol. The structure of hierarchical SAPO-34 was characterized by XRD, N 2 physisorption, mercury intrusion, SEM, TEM, as well as 27 Al, 29 Si, 31 P MAS NMR spectra and compared with a conventional SAPO-34. More Si islands were formed via combined SM3 (Al+P pairs substitution by 2Si) and SM2 (P substitution by Si) mechanism for hierarchical SAPO-34 as Si was not fully incorporated into the precursor lamellar phase. NH 3 -TPD showed that hierarchical SAPO-34 has comparable acidic strength to conventional SAPO-34. The obtained hierarchical SAPO-34 is comprised of

Integrating hierarchical porosity over microporous zeotype materials is an effective way to promote their mass transfer properties and catalytic performances. A combined synthetic strategy using small molecular growth inhibitor 1,2,3-hexanetriol and tumbling crystallization condition to generate hierarchically organized SAPO-11 is herein presented. The addition of 1,2,3-hexanetriol in the synthetic gel of SAPO-11 under agitating conditions significantly altered its crystallization behaviour, resulting in the formation of a hierarchically organized architecture. An underlying nonclassical from-shell-to-core crystallization has been disclosed by time-dependent observation of the formation process. The hierarchically self-organized structure has been characterized by a suite of characterization techniques, such as XRD, N2 physisorption, SEM, TEM, mercury intrusion measurements, 27Al, 29Si, 31P MAS NMR and pyridine adsorption IR (Py-IR). The structure featuring barrel-shaped architecture is comprised of aligned 300–400 nm primary building blocks with voids in between, constructing an auxiliary macro-/meso-pore system open to external surfaces. The catalytic performance of Pt supported on hierarchical SAPO-11 in n-heptane hydroisomerization has been assessed, showing that both catalytic activity and isomer yield have been increased with respect to a conventional sample. As the acidity for the hierarchical SAPO-11 is comparable to the conventional sample, the enhancement in catalytic performance is attributed to the small primary crystal size and macro-/meso-pore-connectivity, that are important for mass transfer.

Silicoaluminophosphates SAPO-41 is a superior unidimensional zeotype catalyst used in hydroisomerization. Generation of hierarchically structured SAPO-41 provides an effective way to promote its hydroisomerization selectivity, which is nonetheless difficult to achieve due to the formation of impurities. Herein, we report crystallization of plate-like crystals of pure phase SAPO-41 in a toluene-aqueous biphasic media in the presence of both Pr2NH and oleylamine. The obtained material has a larger adjustable range of silicon content (nSi/(nAl+nSi+nP) = 0.02−0.15), intermediate acidity and reduced diffusion path length along the micropore channel direction. Catalytic tests for n-heptane hydroisomerization on Pt loaded plate-like SAPO-41 crystals showed that the yield of the isomerized products could reach up to 68 %, with respect to 57 % for a control sample. The selectivities for isomers were found to increase with decreasing Si contents and enhanced diffusion properties, suggesting side β-scission reaction was disfavored at reduced acid site density and shortened diffusion path length.

In this study, the impacts of heat curing conditions on the morphology and permeability of polyamide nanofiltration (NF) membranes were comprehensively investigated. The surface chemical composition, morphology, charge property, hydrophilicity and NF performance of the resulting membranes were studied. In order to preserve the instantaneous polyamide layer morphology, freeze drying process was employed after heat curing. Results showed that the surface roughness of the polyamide selective layer increased first and then decreased with curing time. The tunable morphology of polyamide NF membranes can be acquired by adjusting the curing temperature and time. The nascent membrane without heat curing exhibited excellent pure water permeability of 16.7 L m−2 h−1 bar−1 and maintained Na2SO4 rejection of 97.4%. Increasing the curing time, the permeability of the NF membranes was greatly diminished. This work provided novel viewpoint about the effects of heat curing on morphology and permeability for high-performance polyamide NF membrane.

Carbon nanotubes (CNTs) can be well dispersed in an ethanol diluted zeolite precursor and thus encapsulated in the formed dry gel after solvent evaporation. This specially prepared dry gel allows small quantites of CNTs to effectively act as transient inhibitors in the subsequent steam-assisted crystallization of ZSM-5 nanocrystal aggregates with hierarchical porosity. Although finnally separated from zeolite, CNTs can still transiently inhibit the zeolite growth to avoid fusing into a large crystal. The inter-crystalline mesoporosity in hierarchical ZSM-5 is not created by the space occupied by CNTs, but preserved from the mesoporosity formed by nucleation and initial crystallization. Excessive quantities of CNTs are not recommended because their excessive inhibition induces the appearance of amorphous impurity in hierarchical ZSM-5.

Zeolites belong to microporous solids that are widely used as adsorbents, catalysts and catalyst supports. As diffusion in the microspores is slow, it is highly desirable to develop approaches to enhance mass transfer or to avoid the negative effect from mass transfer resistance. In this perspective, we underline pore architecture control for hierarchical zeolite, and spatial locations of metal nanoparticles on zeolite. For solid acid catalysts, the construction of auxiliary porosity in crystalline zeolites leading to the formation of hierarchical zeolite is a promising solution. Most successful pore-architecture construction strategies are based on templating approaches within the classic LaMer crystallization framework, whereas our strategies are based on the non-classic orientated attachment growth mechanism in dry gel crystallization. Organic additives, such as organosilanes, can be incorporated with protozeolite particles to produce hybrid mesocrystals. Combustion of organics in the mesocrystal affords hierarchical beta zeolites, the pore-architecture of which is tunable with respect to additive selection. Such a crystallization based design of pore-architecture merits small primary crystal size and improved pore-connectivity, which have been verified to be the key factors that affect diffusion. On the other hand, for zeolite supported metal catalysts that suffer from deactivation caused by pore blocking, we propose a strategy to avoid the deactivation problem by depositing metal nanoparticles exclusively on the external surfaces of support. This can be achieved by simply leaving the structure directing agents in the pores before supporting metal particles. Side reactions caused by diffusion resistance are minimized, and moreover, the involatile byproducts, if any, do not produce additional diffusion resistance. Such a simple yet effective architecture control significantly prolongs the lifetime of Au/TS-1 catalyst in direct propene epoxidation with H2 and O2. From these demonstrations, it is important to design purpose-orientated zeolite synthesis to enhance mass transfer, for which the architecture plays a key role.

Glycerol-mediated crystallization transforms a steam-treated dry gel used as the mesoporous precursor into a hierarchical ZSM-5 zeolite. The hierarchical ZSM-5 zeolite with auxiliary mesoporosity and acidity exhibits higher activity in the aldol condensation reaction of benzaldehyde with n-butyl alcohol.

Synthesis of hierarchically porous zeolites has drawn intensive interest because of their improved catalytic performance. It is highly desirable to find ways to generate these materials in a low-cost and scalable way for their commercial applications. A solvent evaporation route has been established to synthesize hierarchically porous titanosilicalite-1 (TS-1). In the protocol, hexadecyltrimethoxysilane was added to an ethanolic solution of titanium isopropoxide, tetraethyl orthosilicate and tetrapropylammonium hydroxide, i.e. the embryo solution of TS-1. The solution was subjected to solvent evaporation-induced self-assembly to afford an ordered dry gel. Subsequent steam-assisted crystallization converted the dry gel into a hierarchically porous TS-1. X-ray powder diffraction (XRD), UV–visible diffusive reflectance spectroscopy, N2 physisorption and electron microscopic characterizations have been employed to elucidate the structure. Ti is incorporated into the tetrahedral sites of the MFI structure and mesopores around 20 nm penetrating the crystalline framework are formed. Hexadecyltrimethoxysilane plays a key role in creating mesopores as well as increasing the crystal size. The hierarchically porous TS-1 exhibits improved activity in styrene oxidation and phenol hydroxylation. Copyright © 2014 John Wiley & Sons, Ltd.

Three short-chain organosilanes, i.e., 3-aminopropyltrimethoxy-silane (APTMS), [3-(2-aminoethyl)aminopropyl]trimethoxysilane (AEAPTMS) and phenylaminopropyltrimethoxysilane (PHAPTMS), were used for the synthesis of hierarchically micro-/mesoporous ZSM-5 zeolites by steam-assisted crystallization of silanized dry gels. Corresponding to the different moieties of organosilanes, the obtained hierarchically porous ZSM-5 zeolites have different degrees of mesoporosity and exhibit spherical morphology composed of small nanounits. Among the three organosilanes, PHAPTMS with a bulky cross-section is the most excellent mesopore directing agent. Tracking the structural evolution of PHAPTMS-ZSM-5 during crystallization shows that a large number of mesopores are produced in the initial steaming, but it is confirmed that it does not occur due to the presence of PHAPTMS. This initial mesoporosity is mostly preserved by the PHAPTMS molecules which inhibit the growth of the crystalline phase and suppress the high mobility of aluminosilicate species under the steam atmosphere.

The α-Mn2O3 nanocrystals with uniform morphology prepared by calcining a self-assembly Mn3O4 precursor show higher activity toward CO oxidation. Operando Raman spectroscopy is used to probe the near-surface structure of α-Mn2O3 nanocrystals during the adsorption and oxidation of CO for the first time. A surface phase-transformation from α-Mn2O3 to MnO-like species, as evidenced by the formation of a single band at 498 cm–1, was observed only at or above 300 °C in the presence of CO. This modification is probably due to the loss of lattice oxygen at high temperatures that leads to the surface reconstruction. Very interestingly, a reversible phase-transformation was observed with decreasing the temperature to 25 °C. The shift of the symmetric stretching of Mn2O3 groups (632 → 649 cm–1) due to the adsorption of CO was observed even at room temperature. In addition, the results of the temperature-programmed desorption of O2 (TPD-O2) and temperature-programmed surface reaction (TRSR) indicate that the oxidizin...

Silanized dry gel prepared by solvent evaporation was subjected to steam treatment to synthesize hierarchically porous zeolite Beta. With well dispersed sodium cations (Na+) in ethanol solution and dry gel, zeolite Beta with high degree of crystallinity can be obtained by the steam-assisted crystallization method. Two types of organosilanes, short-chain phenylaminopropyltrimethoxysilane (PHAPTMS) and long-chain hexadecyltrimethoxysilane (HDTMS), were applied to prepare the silanized dry gel and inhibit the crystallization of zeolite Beta. PHAPTMS does not generate appreciable mesopores, whereas HDTMS can successfully create abundant mesopores ranging from 3 to 10 nm, which indicates a greater spatial separation effect of the long-chain moiety than the short-chain counterpart.

Gold nano-particles confined in the walls of mesoporous silica (GMS) catalysts were successfully prepared by a novel and simple technique utilizing thioether functional groups in the walls of mesoporous silica to anchor HAuCl4. Calcination of the materials removed organic moieties and reduced thegold salt to gold nano-particles. In this procedure, the thioethergroups were introduced into the silicawall via a co-condensation of tetraethyl orthosilicate (TEOS) with 1,4-bis(triethoxysily)propane tetrasulfide. These gold containing mesoporous catalysts have unusually high surface area and porevolume. The catalysts were evaluated for the solventfree liquid phase oxidation of benzyl alcohol bymolecular oxygen. High selectivity to benzaldehyde was obtained under the reaction conditions of 403 K, 15 atm and 5 h in an autoclave. The 1.5% GMS catalyst was also evaluated for oxidation of alcohols using toluene as solvent under flowing oxygen at atmospheric pressure at 353 K in a two-necked flask. Under these conditions the conversion of benzyl alcohol reached 100% after 2 h and it was demonstrated that the catalyst can be recycled three times without significant loss of activity. # 2007 Elsevier B.V. All rights reserved.

We report the synthesis and characterization of a series of new mesoporous zeolite and zeotype materials made available by combining new and improved procedures for directly introducing carbon into reaction mixtures with the fluoride route for conventional zeolite synthesis. The mesoporous materials were all prepared by hydrothermal crystallization of gels adsorbed on carbon matrices which were subsequently removed by combustion. The procedures presented here resulted in mesoporous zeolite and zeotypes materials with MFI, MEL, BEA, AFI and CHA framework structures. All samples were characterized by XRPD, SEM, TEM and N2 physisorption measurements. For the zeolite materials it was found that mesoporous MFI and MEL structured single crystals could indeed be crystallized from fluoride media using an improved carbon-templating approach. More importantly, it was found that mesoporous BEA-type single crystals could be crystallized from fluoride media by a newly developed procedure presented here. Thus, we here present the only known route to mesoporous BEA-type single crystals, since crystallization of this framework structure from basic media is known to give only nanosized crystals as opposed to mesoporous single crystals. For the zeotype materials it was found that highly crystalline mesoporous materials of AFI and CHA structure types could be synthesized using a newly developed procedure.

A route to generate hierarchically porous zeolite ZSM-11 has been paved via solvent evaporation induced self-assembly assisted by hexadecyltrimethoxysilane to produce a preformed dry gel, followed by its subsequent transformation into zeolite via steam-assisted-crystallization. The crystallization in dry gel has been found to undergo an orientated attachment growth mechanism whereby hexadecyltrimethoxysilane directs the formation of auxiliary mesopores and inhibits the fusion of primary nucleates. Measurements such as XRD, SEM, TEM, N2-physisorption, and TEM for an inverse replica of Pt derived from hierarchical ZSM-11 have been conducted to characterize the textural properties of the material. Ammonia temperature-programmed-desorption (NH3-TPD) measurements and infrared spectra using probe molecules such as pyridine (Py-IR) and 2,4,6-collidine (Coll-IR) have been collected to investigate the acidic properties as well as the accessibility of the acid sites. The hierarchical ZSM-11 possesses more acid sites on the mesopore surfaces that are accessible towards large probe molecules such as 2,4,6-collidine. This improvement together with the enhanced pore-connectivity brings about an increase in 1,3,5-triisopropylbenzene cracking activity and benzene selectivity with respect to a conventional counterpart.

Imidazole type ionic liquid 1-hexadecyl-3-methylimidazolium chloride and 1-hexadecyl-3-methylimidazolium ruthenium hexachloride were used to fabricate the well-ordered hexagonal mesoporous silica (under acidic and basic conditions), and Ru–SiO 2 , respectively. Small angle X-ray diffraction, scanning electron microscopy, transmission electron microscopy and N 2 adsorption–desorption were employed to characterize the structure. The mesoporosity of the silica matrix is preserved after calcination of organic templates. The pore diameter of silica prepared from acidic media (2.20 nm) was smaller and less ordered than that of silica from basic solution (2.74 nm). Further, the mesoporous structure of Ru–SiO 2 was found to be preserved after calcination, however, RuO 2 nanoparticles formed in the matrix of mesoporous silica upon calcination.

Bis(1,5-cyclooctadiene) nickel [Ni(COD)2] was employed as a nickel precursor to prepare nickel oxide nanoparticles upon high-surface-area mesoporous silica. Under protection of argon, Ni(COD)2 was dissolved in tetrahydrofuran (THF) to react with surface silanols of mesoporous silica SBA-15, which formed a black powder after completion of the surface reaction. Calcination of the powder produced ultrafine NiO inside the mesoporous silica matrix, which was evidenced by X-ray diffraction, N2 adsorption–desorption, transmission electron microscopy and thermogravimetric analysis. The thermogravimetric analysis suggests that NiO formation is a result of surface nickel species calcination, whereas structural characterization clearly show that NiO nanoparticles of

A simple procedure applying crystallization of zeolites around a combustible carbon matrix generated in situ from sugar deposited onto mesoporous silica gel offers good perspectives for the large-scale preparation of mesoporous zeolites.

The cover picture shows a novel method for producing mesoporous zeolite single crystals by using cheap and easily prepared porous carbon as the mesopore template. The porous carbon template was obtained by carbonization in Ar of a hydrothermally treated sucrose/ammonia mixture, and it was successfully applied as an inert carbon matrix during zeolite crystallization. After hydrothermal crystallization, combustion of the carbon embedded in the zeolite crystals yielded mesoporous zeolite single crystals. Details are discussed in the article by C. H. Christensen et al. on p. 3955 f.