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The separation of layered MFI into unilamellar nanosheets in solution confirms the general validity of soft-chemical exfoliation for zeolites and allows top-down production of films with potential applications in separation and catalysis.

Selective hydrogenation catalysts play a key role in many industrial processes, but they are primarily based on supported noble metals, such as Pt and Pd, which are usually dispersed in nanoparticles. However, the production and recovery of these noble metal nanoparticles is a very energy-consuming and expensive procedure. Accordingly, replacing these metals by other inexpensive, transition metals such as Fe and Cu without sacrificing the activity and selectivity, will necessarily reduce their production costs. Moreover, zeolites as a support provide the advantage of shape selectivity to the desired product. In this study, we develop an alternative method for preparing hydrogenation catalysts composed of metallic nanoparticles encapsulated into zeolite frameworks through reductive demetallation of Fe-zeolites or Cu/Fe-zeolites with MFI topology. Particularly, the process of reductive demetallation is described using temperature-programmed reduction (TPR) and Mossbauer spectroscopy data. The reductive demetallation of Fe-MFI, consisting of Fe extraction from the zeolite framework and formation of Fe0 nanoparticles, starts at the temperatures above 800 ℃ and finishes at 1030 ℃, when sintering occurs strongly. In contrast, introduction of second metal leads to the decrease in the reduction temperature, as process of CuFe@MFI formation finishes at 800 ℃. Both Fe@MFI and CuFe@MFI show activity in p-nitrotoluene hydrogenation to p-toluidine. Conversion of the substrate grows with increase in the Cu and Fe loading. Thus, this synthesis method of encapsulation of Fe0 nanoparticles and Fe0-Cu0 bimetallic nanoparticles into the zeolite micropores through reductive demetallation of Fe-zeolites can be used to prepare hydrogenation catalysts.

Nanoporous crystalline aluminosilicates, zeolites, are synthesised by solvothermal method producing three-dimensional (3D) crystals. An alternative, more controllable approach of zeolite synthesis - ADOR – can be used for preparation of isoreticular zeolites with tuneable porosity. Zeolites porosity allows their wide use as isomerisation catalysts due to their shape selectivity effects. Selective isomerisation of m-xylene towards p-xylene is an industrially important reaction due to a high demand for the latter as a substrate for terephthalic acid production. In this work, we investigated the influence of pore size (shape selectivity effect) on the isomerization of m-xylene using a system of isoreticular Al-containing zeolites. These materials, prepared by ADOR approach (UTL, IPC-7, IPC-2, IPC-6, and IPC-4) had different layers connectivity, and therefore various channel systems. We tracked the influence of the pore systems of ADOR zeolites (8- up to 14-ring channels) on the catalytic performance in gas-phase m-xylene isomerisation. We investigated the crystallinity and interlayer distances, phase purity, textural properties of prepared materials, their crystals morphology, and aluminium content. M-xylene isomerisation was carried out in a fixed-bed reactor at 350 °C. ADOR catalysts were compared with standard ZSM-5 zeolite. We show the dependence of zeolite porosity on the performance in isomerisation of m- to p-xylene. Smaller pore zeolites: IPC-4 (8- and 10-ring channels) and IPC-6 (8-, 10- and 12-ring channels) exhibited the lowest conversions, while the highest conversion and p-xylene yields were observed for IPC-2 (10- and 12-ring channels). Presence of extra-large, 14-ring channels (IPC-7 and UTL) resulted in the drop of selectivity due to the xylene disproportionation.

Palladium nanoparticles entrapped in porous aromatic frameworks (PAFs) or covalent organic frameworks may promote heterogeneous catalytic reactions. However, preparing such materials as active nanocatalysts usually requires additional steps for palladium entrapment and reduction. This paper reports as a new approach, a simple procedure leading to the self-entrapment of Pd nanoparticles within the PAF structure. Thus, the selected Sonogashira synthesis affords PAF-entrapped Pd nanoparticles that can catalyze the C-C Suzuki-Miyaura cross-coupling reactions. Following this new concept, PAFs were synthesized via Sonogashira cross-coupling of the tetraiodurated derivative of tetraphenyladamantane or spiro-9,9'-bifluorene with 1,6-diethynylpyrene, then characterized them using powder X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy, X-ray photoelectron spectroscopy, high-resolution scanning transmission electron microscopy, and textural properties (i.e., adsorption-desorption isotherms). The PAF-entrapped Pd nanocatalysts showed high catalytic activity in Suzuki-Miyaura coupling reactions (demonstrated by preserving the turnover frequency values) and stability (demonstrated by palladium leaching and recycling experiments). This new approach presents a new class of PAFs with unique structural, topological, and compositional complexities as entrapped metal nanocatalysts or for other diverse applications.

Extra-large pore zeolites clear the way for the synthesis of fine chemicals and bulky compounds unable to enter the channels of medium- and large-pore zeolites.

Recently reported groundbreaking discovery of efficient delamination of zeolite MCM-56, producing colloidal suspensions of MWW monolayers dispersed in the liquid phase, created unprecedented possibilities for the synthesis of a zeolite catalyst. Based on this innovation, the concept of using MWW monolayers to prepare silica-supported zeolite nanosheet catalysts suitable for transformations of large organic molecules was explored in this work. A series of silica-MWW preparations was synthesized from colloidal suspensions of the monolayers, using both solid and colloidal silica sources. The synthesized solids were thoroughly characterized with various physicochemical methods and their catalytic performance was tested in alkylation of mesitylene with benzyl alcohol. The obtained results indicate that solids containing MWW layers dispersed on silica show promising catalytic properties. The mixed MWW:silica catalysts synthesized from dispersions of MWW monolayers and liquid silica were found to exhibit high specific catalytic activity (with TOF values of 3.4 × 10−3 to 4.8 × 10−3 s−1), despite the high content of inactive amorphous silica support (40–60%). Materials synthesized from solid fumed and precipitated silicas showed low or negligible overall activity, which could be attributed to the small incorporation of the zeolitic active phase. For one of such materials, a notable high TOF (4.8 × 10−3 s−1) was found. It was found earlier that ethanol is an effective flocculent for zeolite layers by themselves, but in the presence of solid silica its efficiency was reduced.

Supported metal nanoparticles are widely used as heterogeneous catalysts but often deactivated due to sintering under harsh conditions, especially at high temperatures. Sintering can be prevented by confining metal species into a porous matrix, although supports rarely provide additional stabilization effects. Herein, we used silanol-rich layered zeolite, IPC-1P, to stabilize ultra-small Rh nanoparticles. By adjusting the interlayer space of the precursor through swelling, we prepared various architectures, including microporous Rh@IPC-4_C12 and disordered mesoporous Rh@IPC_C22. By in-situ scanning transmission electron microscopy, we confirmed that immobilized Rh nanoparticles are resistant to sintering at high temperatures (650 oC for 2hrs). Our density functional theory (DFT) calculations indicated that small Rh clusters strongly bind to the surface silanol quadruplets at IPC-1P layers through hydrogen transfer to the metallic particles, while high silanol density hinders migration on the surface. Ultimately, combining swelling with long-chain surfactant and utilizing metal-silanol interactions resulted in a novel, catalytically active zeolitic material termed Rh@IPC_C22.

Developing highly efficient electrocatalysts for electrochemical CO

Developing highly efficient electrocatalysts for electrochemical CO2 reduction (ECR) to value-added products is important for CO2 conversion and utilization technologies. In this work, a sulfur-doped Ni−N−C catalyst is fabricated through a facile ion-adsorption and pyrolysis treatment. The resulting Ni−NS−C catalyst exhibits higher activity in ECR to CO than S-free Ni−N−C, yielding a current density of 20.5 mA cm−2 under −0.80 V versus a reversible hydrogen electrode (vs. RHE) and a maximum CO faradaic efficiency of nearly 100 %. It also displays excellent stability with negligible activity decay after electrocatalysis for 19 h. A combination of experimental investigations and DFT calculations demonstrates that the high activity and selectivity of ECR to CO is due to a synergistic effect of the S and Ni−NX moieties. This work provides insights for the design and synthesis of nonmetal atom-decorated M−N−C-based ECR electrocatalysts.

The application of the Assembly–Disassembly–Organization–Reassembly (ADOR) protocol to the synthesis of germanosilicate zeolites has become a major milestone in material design by enabling the prep...

Confining Au nanoparticles (NPs) in a restricted space (

Purpose Indium tin oxide (ITO) is a material belonging to the group of transparent conductive oxides, which are widely used in many fields of technology including optoelectronics and photovoltaics. However, the properties of ITO thin films depend on many factors. Therefore, the aim of the study was thorough investigation of the properties of sputtered ITO thin films of various thicknesses. Design/methodology/approach ITO coatings were deposited by magnetron sputtering in pure argon atmosphere using ceramic ITO target. Various deposition times resulted in obtaining thin films with different thickness, which had significant influence on the optoelectronic properties of deposited coatings. In this work the results of investigation of structural, surface, optical and electrical properties were presented. Findings Increase of the coating thickness caused change of the microstructure from amorphous to nanocrystalline and occurrence of grains with a size of 40 to 60 nm on their surface. Moreover, the fundamental absorption edge was red-shifted, whereas the average transmission in the visible wavelength range remained similar. Increase of the thickness caused considerable decrease of the sheet resistance and resistivity. It was found that even thin films with a thickness of 10 nm had antistatic properties. Originality/value The novelty and originality of presented work consists in, among other, determination of antistatic properties of ITO thin films with various sheet resistances that are in the range typical for dielectric and semiconducting material. To date, there are no reports on such investigations in the literature. Reported findings might be very helpful in the case of, for example, construction of transparent antireflective and antistatic multilayers.

Germanosilicate zeolites with extra-large-/multidimensional pore systems have a high potential for catalytic applications. However, their insufficient hydrothermal stability, high cost, and lack of...

Polymeric carbon/activated carbon aerogels were synthesized through sol-gel polycondensation reaction followed by the carbonization at 800 °C under Argon (Ar) atmosphere and subsequent physical activation under CO2 environment at different temperatures with different degrees of burn-off. Significant increase in BET specific surface area (SSA) from 537 to 1775 m2g−1 and pore volume from 0.24 to 0.94 cm3g−1 was observed after physical activation while the pore size remained constant (around 2 nm). Morphological characterization of the carbon and activated carbons was conducted using X-ray diffraction (XRD) and Raman spectroscopy. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to investigate the effect of thermal treatment (surface cleaning) on the chemical composition of carbon samples. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to analyse the capacitive and resistive behaviour of non-activated/activated/and surface cleaned activated carbons employed as electroactive material in a two electrode symmetrical electrochemical capacitor (EC) cell with 6 M KOH solution used as the electrolyte. CV measurements showed improved specific capacitance (SC) of 197 Fg−1 for activated carbon as compared to the SC of 136 Fg−1 when non-activated carbon was used as electroactive material at a scan rate of 5 mVs−1. Reduction in SC from 197 Fg−1 to 163 Fg−1 was witnessed after surface cleaning at elevated temperatures due to the reduction of surface oxygen function groups. The result of EIS measurements showed low internal resistance for all carbon samples indicating that the polymeric carbons possess a highly conductive three dimensional crosslinked structure. Because of their preferred properties such as controlled porosity, exceptionally high specific surface area, high conductivity and desirable capacitive behaviour, these materials have shown potential to be adopted as electrode materials in electrochemical capacitors.

In this contribution, zeolites with different pore sizes and connectivity (MFI 10-10-10R, MTW 12R, Beta 12-12-12R) were prepared in bulk and hierarchical “nanosponge” form and with different composition (aluminosilicate, gallosilicate). Properties of the samples were characterized by X-ray diffraction, argon adsorption, transmission electron microscopy and adsorption of pyridine followed by FTIR spectroscopy. Catalytic performance (conversion of reactants, yields of products and turn-over frequencies) of prepared materials was investigated in the Pechmann condensation of resorcinol with ethyl acetoacetate. The lowest conversion (less than 15%) over the MFI samples suggests that its 10R channels are too narrow for the products to escape from the framework and thus the reaction proceeds mainly on the crystal surface. Conversion of reactants over MTW and Beta zeolites is higher (10%, 35%, 71% and 69% for bulk MTW, nanosponge MTW, bulk Beta and nanosponge Beta, respectively), however, undesired side-products are formed. The hierarchical form of MFI and MTW gives higher conversions and yields of products than their bulk counterparts. Interestingly, the difference between bulk and hierarchical Beta is negligible. The overall performance of aluminosilicates and gallosilicates in the reaction is comparable. Catalytic activity of the samples was determined mainly by their textural properties.

Hydrogenation of nitroarenes is a catalytic reaction of high interest owing to the importance of the resulting aromatic amines in the chemical industry. Up to date, various metal@zeolite catalysts have been reported for this transformation. Herein, Pd@Beta and Pd@MWW catalysts were synthesized by ion exchange with Pd(NH3)4(NO3)2 and characterized by XRD, nitrogen sorption, ICP-OES, electron microscopy and FTIR(CO). Structural and textural analysis proved no significant changes of the zeolites after the Pd precursor was introduced. STEM images proved the uniform distribution of metal species in zeolite crystals. Average size of Pd NPs is 2.6 nm and 1.7 nm for Beta and MWW zeolites, respectively. The resulting Pd@Beta catalyst exhibited higher catalytic activity compared to Pd@MWW in the hydrogenation of nitroarenes. The electronic/steric effects of substrates and products were also investigated for both catalysts. Nitroarenes with electron-donating groups exhibit higher initial reaction rates than nitroarenes containing electron-withdrawing groups. The nitroarenes bearing functionalized groups in the ortho-position are harder to hydrogenate than corresponding meta- and para- isomers because of the steric hindrance effect.

This article demonstrates preparation of metal functionalized zeolite catalysts via a new homogeneous solution pathway enabled by the recently reported exfoliation of zeolite MWW into solution of unilamellar nanosheets. The preparation is carried out by mixing solutions of exfoliated MWW monolayers and Pt nanoparticles with initial size of ca 3 nm and isolation of such hybrid catalysts by freeze-drying. Optionally, the MWW layer solutions were purified by dialysis prior to mixing with the metal solution, which turned out to be beneficial for quality and textural characteristics. However, catalytic performance in the model reaction – 3-nitrotoluene hydrogenation, was mostly determined by the Pt level, i.e. at least 0.3%, and less affected by the apparent quality of the final zeolite support. The catalysts revealed agglomeration of the Pt nanoparticles from roughly 3 nm to between 5 and 10 nm.

Performed reverse engineering analysis showed the complex dependence of the optical properties on the material composition and the microstructure properties of the (Ti,Cu)Ox gradient thin film prepared using multi-magnetron co-sputtering.

The paper presents the results of the analysis of resistive switching properties observed in (Ti-Cu)-oxide thin film with gradient distribution of elements over the thin film thickness. Thin films were prepared using the multisource reactive magnetron co-sputtering process. Programmed profile of the pulse width modulation coefficient during sputtering of the Cu target allowed to obtain the designed gradient U-shape profile of Cu concentration in the deposited thin film. Electrical measurements of Au/(Ti-Cu)Ox/TiAlV structure showed the presence of nonpinched hysteresis loops in the voltage–current plane testifying the resistive switching behavior. Additionally, the initial forming process of conducting filaments has been observed as well. Optical, x-ray, and ultraviolet photoelectron spectroscopy measurements allowed to create the scheme of the bandgap alignment of the prepared thin films with respect to the Au and TiAlV electrical contacts. Detailed structure and elemental profile investigations allowed to conclude about the presence of conducting filaments of the observed resistive switching mechanism occurring in the prepared test structure. The obtained results showed that the prepared gradient (Ti-Cu)Ox thin film could be an interesting alternative to the conventional multilayer stack construction of resistive switching devices.

Cerium oxide nanoparticles (CeNPs) possess multiple redox enzyme mimetic activities in scavenging reactive oxygen species (ROS) as a potential biomedicine. These enzymatic activities of CeNPs are closely related to their surface oxidation state. Here we have reported a synthetic method to modify CeNPs’ surface oxidation state by changing the conformation of the poly(acrylic acid) (PAA) polymers adsorbed onto the CeNP surface. The synthesized PAA–CeNPs exhibited the same core size, morphology, crystal structure, and colloidal stability, with the only variation being their surface oxidation state (Ce3+ percentage). The modification mechanism can be attributed to the polymers chemisorbed onto the metal oxide surface forming a metal complexation structure. Such adsorption further modified CeNPs’ surface oxidation state in a temperature-dependent manner. The series of PAA–CeNPs exhibited multiple redox enzyme mimetic activities (superoxide dismutase, catalase, peroxidase, and oxidase) directly related to their surface oxidation state. In vitro experiments showed no cytotoxic effect of these PAA–CeNPs on the osteoblastic cell line SAOS-2 at high loadings. Microscopic images confirmed the internalization of PAA–CeNPs in the cells. All tested PAA–CeNPs can reduce the basal and hydrogen peroxide-induced intracellular ROS level in the cells, indicating their effective intracellular ROS scavenging effect. However, we did not observe a positive correlation between the CeNP surface oxidation state and their capacities to reduce the intracellular ROS levels. We propose that CeNPs can maintain a dynamic state of Ce3+/Ce4+ during their catalytic activities, exhibiting a non-linear correlation between the CeNP surface oxidation state and their effect on regulating the intracellular ROS level.

Zeolite molecular sieves are widely used in gas separation and shape-selective catalysis, but these applications often require discriminating differences as little as 0.1 A. Molecular sieving with such size selectivity demands zeolites with highly tunable pore diameters and adsorption properties, which are technically challenging to prepare. Nevertheless, it is shown that a wide range of organic functional groups can be covalently functionalized onto the interior pore walls of the zeolites, MOR, LTL, FAU, and MFI, to systematically "tune" their effective pore diameters with respect to the size of organic groups. For organic functionalization, small and aggressive organic electrophiles are used (e.g., organo-halide and -diazonium) as grafting agents, which are accessible to the intracrystalline void space, forming a C-Ozeolite bond in a reaction with a bridging oxygen as proved by multiple analysis data. It is demonstrated that the post-functionalization can be used to tailor the molecular sieving action of a parent zeolite to give size-selective adsorbents for light olefin/paraffin separations. 4-Methoxybenzene-functionalized MOR separates ethylene from ethane with an ideal-adsorbed-solution-theory selectivity of ≈5873, whereas toluene-grafted MOR completely separates propylene/propane mixtures. Therefore, tailoring the molecular-sieving properties of zeolites by organic functionalization broadens their applications to challenging separations.

Direct exfoliation of layered zeolites into solutions of monolayers has remained unresolved since the 1990s. Recently, zeolite MCM-56 with the MWW topology (layers denoted mww) has been exfoliated directly in high yield by soft-chemical treatment with tetrabutylammonium hydroxide (TBAOH). This has enabled preparation of zeolite-based hierarchical materials and intimate composites with other active species that are unimaginable via the conventional solid-state routes. The extension to other frameworks, which provides broader benefits, diversified activity, and functionality, is not routine and requires finding suitable synthesis formulations, viz. compositions and conditions, of the layered zeolites themselves. This article reports exfoliation and characterization of layers with ferrierite-related structure, denoted bifer, having rectangular lattice constants like those of the FER and CDO zeolites, and thickness of approximately 2 nm, which is twice that of the so-called fer layer. Several techniques were combined to prove the exfoliation, supported by simulations: AFM; in-plane, in situ, and powder X-ray diffraction; TEM; and SAED. The results confirmed (i) the structure and crystallinity of the layers without unequivocal differentiation between the FER and CDO topologies and (ii) uniform thickness in solution (monodispersity), ruling out significant multilayered particles and other impurities. The bifer layers are zeolitic with Bronsted acid sites, demonstrated catalytic activity in the alkylation of mesitylene with benzyl alcohol, and intralayer pores visible in TEM. The practical benefits are demonstrated by the preparation of unprecedented intimately mixed zeolite composites with the mww, with activity greater than the sum of the components despite high content of inert silica as pillars.

The paper presents a discussion on memristive-like properties observed in metal/semiconducting-oxide/metal structure containing a semiconducting (TixCu1-x)Ox thin film with asymmetrical elemental Cu distribution over the thin film thickness. The thin film was prepared using a combinatorial multi-magnetron sputtering process. Based on current-to-voltage electrical investigations, a sharp forward-to-open rectifying behaviour was observed with a hysteresis loop in the forward bias conditions only. Detailed structure and elemental profile investigations allowed to propose explanation of observed type of resistive transition.

Zeolites with encapsulated metal nanoparticles (NPs) attract much attention due to the catalytic activity, stability and shape-selective properties of such materials in heterogeneous catalysis. One of the methods for introduction of metal NPs into the zeolite system is based on use of two dimensional (2D) layered precursors that are loaded with Pt source and consecutively transformed to three dimensional (3D) zeolites. This method can be combined with recently developed approach for zeolite synthesis; the ADOR (Assembly, Disassembly, Organization, and Reassembly) approach that is based on the 3D-2D-3D transformation of zeolites. Here, we report a synthesis of two ADOR zeolites: IPC-2 (OKO topology) and IPC-4 (PCR topology) functionalized with Pt NPs, Pt@IPC-2 and Pt@IPC-4, respectively. Pt@IPC-2 was prepared by intercalation of platinum(0)-2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetra siloxane into IPC-1P layered precursor and subsequent calcination. Pt@IPC-4 zeolite was prepared by the swelling of IPC-1P with the mixture of surfactant and Pt source. Final materials were investigated by XRD, nitrogen sorption, ICP-OES, and electron microscopy (SEM and STEM). Structural and textural analysis confirmed the successful syntheses of two ADOR zeolites. The size and distribution of Pt NPs were investigated by STEM. The platinum content was 0.34 wt% and 0.32 wt% and the average size of Pt NPs of 0.98 nm and 0.96 nm for Pt@IPC-2 and Pt@IPC-4, respectively. Pt@IPC-2 exhibited a broader range of Pt sizes due to larger pores.

Nitrogen doped resorcinol/formaldehyde carbon aerogels with controlled nitrogen content are synthesized by controlling the resorcinol/melamine molar ratio (R/M) during the synthesis of aerogel precursors. The carbons were used as electrode materials in an electrochemical capacitor using 6 M KOH solution as electrolyte. All samples exhibited amorphous structure with low degree of graphitization. The maximum specific capacitance of 208 Fg-1 was observed after doping of the carbon with nitrogen at R/M = 80. Drop in solution and charge transfer resistances from 0.57Ω to 0.15Ω and 0.05Ω–0.04Ω was also observed respectively, with the drop in contact angles from 123° to 103° for the carbon doped with nitrogen at R/M = 80. BET results showed that the pore volume and surface area of carbon increase after N-doping, with a BET surface area of 841 m2 g−1 at R/M = 80. This R/M ratio is an optimum ratio at which incorporation of nitrogen into the carbon matrix improves the capacitive performance of cell as a result of improved porosity/wettability/conductivity/active sites of the electrode. Doping at higher nitrogen concentrations (R/M

Zeolites have become indispensable materials for chemical industry being applied as detergents, adsorbents and particularly catalysts. Over the past decades this broad research and application field has experienced rapid development. New zeolite structures were synthesized, fundamental knowledge of micro- and mesoporous materials synthesis and characterization was substantially deepened and, consequently, more economical and environmentally acceptable industrial technologies were developped. This chapter summarizes the fundamental as well as practical aspects of zeolite synthesis, the most important properties of zeolites and their implications for practical use together with the main industrial applications. In particular, the attention is focused on zeolite use as adsorbents and catalysts. Zeolite research field was broadened to related materials, including zeotypes, mesoporous molecular sieves, hierarchic systems and metal-organic-frameworks. Synthesis, properties, and application potential of these novel and exciting groups of porous molecular sieves are briefly highlighted as well. Keywords: Zeolites; Mesoporous materials; Hierarchic systems; Catalysis; Adsorption

The paper discusses the preparation of multicomponent thin films of Cu-Ti composite with desired elemental composition using the pulsed magnetron co-sputtering technology. The technological goal described in the paper was deposition the Cu-Ti composite with elemental ratio of about 50/50 at%, which is close to the eutectic point from the Cu-Ti alloy system. A large difference in the sputtering yield (about seven-fold) of Cu and Ti metals was challenging, because of the features of used power supplies. Desired concentrations of the Ti and Cu elements were obtained as a result of application of multimagnetron sputtering system, where magnetrons were equipped with the Ti or Cu targets. Additionally, pulse power supply was used together with the pulse width modulation controller. Moreover, the article presents investigations of structural and mechanical properties of deposited Cu, Ti and Cu-Ti films with elemental composition of ca. 50/50 at.%. It was found that the two component Cu0.5Ti0.5 thin films were composed of Cu4Ti3 nanocrystallites built-in an amorphous matrix. As compared to the pure Cu and Ti thin films, the prepared composite exhibited improved hardness and better elasticity reflected in lower values of the Young's modulus. The results of nanoindentation investigations showed that the Cu0.5Ti0.5 composite thin film was characterized by the hardness of 7.59 GPa.

Zeolites doped with metal nanoparticles have shown the outstanding activity in many processes involving heterogeneous catalysis. The size of metal nanoparticles plays a decisive role in the performance of zeolite catalysts. However, the precise control of the size of nanoparticles is still limited. Herein, we present the synthesis of Pt-MWW zeolites with controllable nanoparticle size using a series of surfactants with different alkyl chain lengths for swelling of layered MCM-22 P. The interlayer distances of swollen materials increases with the length of the surfactant from 1.06 nm (C12OH) to 2.89 nm (C18OH). During swelling, the Pt nanoparticles were intercalated to the interlayer space of MCM-22 P. Further calcination resulted in Pt-MWW materials showing similar morphologies, textural properties and Pt content despite the differences in the initial interlayer distances. The factor that differentiated the synthesized materials was the average diameter of metal nanoparticles. As a result, the average size of Pt nanoparticles increased from 0.85 nm (MCM-22-C12OH-Pt) to 2.04 nm (MCM-22-C18OH-Pt) which is related to the length of the hydrocarbon chain of the surfactant used for the swelling process.