Catalysts for the Conversion of CO to Low Molecular Weight Olefins-A Review.

There is a large worldwide demand for light olefins (C-C), which are needed for the production of high value-added chemicals and plastics. Light olefins can be produced by petroleum processing, direct/indirect conversion of synthesis gas (CO + H) and hydrogenation of CO. Among these methods, catalytic hydrogenation of CO is the most recently studied because it could contribute to alleviating CO emissions into the atmosphere.

Conjugation with carbon nanotubes improves the performance of mesoporous silicon as Li-ion battery anode.

Carbon nanotubes can be utilized in several ways to enhance the performance of silicon-based anodes. In the present work, thermally carbonized mesoporous silicon (TCPSi) microparticles and single-walled carbon nanotubes (CNTs) are conjugated to create a hybrid material that performs as the Li-ion battery anode better than the physical mixture of TCPSi and CNTs. It is found out that the way the conjugation is done has an essential role in the performance of the anode.

Cycloaddition of Nitrile Oxides to Graphene: a Theoretical and Experimental Approach.

Density functional theory (DFT) studies of the interaction between graphene sheets and nitrile oxides have proved the feasibility of the reaction through 1,3-dipolar cycloaddition. The viability of the approach has been also confirmed experimentally through the cycloaddition of few-layer exfoliated graphene and nitrile oxides containing functional organic groups with different electronic nature. The cycloaddition reaction has been successfully achieved in one-pot from the corresponding oximes under microwave (MW) irradiation.

Modulating charge carrier density and mobility in doped graphene by covalent functionalization.

Covalent B-functionalization of B-doped graphene has been performed for the first time. The electronic properties and Hall effect of functionalized N- and B-doped graphene can be tuned by tailoring the electron-donating/-withdrawing properties of the organic addend.

Na-doped ruthenium perovskite electrocatalysts with improved oxygen evolution activity and durability in acidic media.

The design of active and durable catalysts for the HO/O interconversion is one of the major challenges of electrocatalysis for renewable energy. The oxygen evolution reaction (OER) is catalyzed by SrRuO with low potentials (ca. 1.

Partial Oxidation of Methane to Syngas Over Nickel-Based Catalysts: Influence of Support Type, Addition of Rhodium, and Preparation Method.

There is great economic incentive in developing efficient catalysts to produce hydrogen or syngas by catalytic partial oxidation of methane (CPOM) since this is a much less energy-intensive reaction than the highly endothermic methane steam reforming reaction, which is the prominent reaction in industry. Herein, we report the catalytic behavior of nickel-based catalysts supported on different oxide substrates (AlO, CeO, LaO, MgO, and ZrO) synthesized via wet impregnation and solid-state reaction. Furthermore, the impact of Rh doping was investigated.

N-Doped graphene/C covalent hybrid as a new material for energy harvesting applications.

N-Doped graphene (N-G) was chemically functionalized by -alkylation with the well-known electron acceptor C. The degree of functionalization and the key structural features of the N-G/C hybrid were systematically investigated by a number of techniques including thermogravimetric analysis, X-ray photoelectron and Raman spectroscopies and transmission electron and atomic force microscopies. Absorption and electrochemical studies revealed interactions between the N-G and C while the fluorescence of C within the hybrid was found to be fully quenched.

Resource Recovery Potential From Lignocellulosic Feedstock Upon Lysis With Ionic Liquids.

Lignocellulosic residues from energy crops offer a high potential to recover bioproducts and biofuels that can be used as raw matter for agriculture activities within a circular economy framework. Anaerobic digestion (AD) is a well-established driver to convert these residues into energy and bioproducts. However, AD of lignocellulosic matter is slow and yields low methane potential, and therefore several pre-treatment methods have been proposed to increase the energy yield of this process.

CO Oxidation at 20 °C on Au Catalysts Supported on Mesoporous Silica: Effects of Support Structural Properties and Modifiers.

In this work we report the effects of support structural properties and its modification with some metal oxides modifiers on the catalytic behavior of Au catalysts in the total CO oxidation at 20 °C. Au catalysts were supported on mesoporous silica materials (MSM) having different structural properties: Channel-like (SBA-15), cage-like (SBA-16), hexagonal (HMS), and disordered (DMS-1) structures. The effect of the modifier was evaluated by comparison of the catalytic response of the SBA-15-based catalysts modified with MgO, Fe₂O₃, TiO₂, and CeO₂.

Edge-on and face-on functionalized Pc on enriched semiconducting SWCNT hybrids.

Enriched semiconducting single-walled carbon nanotubes (SWCNT (6,5) and SWCNT (7,6)) and HiPco nanotubes were covalently functionalized with either zinc phthalocyanine or silicon phthalocyanine as electron donors. The synthetic strategy resulted in edge-on and face-on geometries with respect to the phthalocyanine geometry, with both phthalocyanines held by an electronically conducting diphenylacetylene linker. The extent of functionalization in the MPc-SWCNT (M = Zn or Si) donor-acceptor nanohybrids was determined by systematic studies involving AFM, TGA, XPS, optical and Raman techniques.

Bioinspired Electro-Organocatalytic Material Efficient for Hydrogen Production.

Commercial carbon fibers can be used as electrodes with high conductive surfaces in reduced devices. Oxidative treatment of such electrodes results in a chemically robust material with high catalytic activity for electrochemical proton reduction, enabling the measurement of quantitative faradaic yields (>95 %) and high current densities. Combination of experiments and DFT calculations reveals that the presence of carboxylic groups triggers such electrocatalytic activity in a bioinspired manner.

Direct Detection of OXA-48 Carbapenemase Gene in Lysate Samples through Changes in Mechanical Properties of DNA Monolayers upon Hybridization.

Carbapenem-resistant Enterobacteriaceae have recently become an important cause of morbidity and mortality due to healthcare-associated infections. Most commonly used diagnostic methods are incompatible with fast and accurate directed therapy. We report here the direct identification of the bla gene, which codes for the carbapenemase OXA-48, in lysate samples from Klebsiella pneumoniae.

Targeted killing of prostate cancer cells using antibody-drug conjugated carbon nanohorns.

The ability of carbon nanohorns (CNHs) to cross biological barriers makes them potential carriers for delivery purposes. In this work, we report the design of a new selective antibody-drug nanosystem based on CNHs for the treatment of prostate cancer (PCa). In particular, cisplatin in a prodrug form and the monoclonal antibody (Ab) D2B, selective for PSMA cancer cells, have been attached to CNHs due to the current application of this antigen in PCa therapy.

Dissolution Kinetics of Hot Compressed Oxide Glasses.

The chemical durability of oxide glasses is an important property for a wide range of applications and can in some cases be tuned through composition optimization. However, these possibilities are relatively limited because around 3/5 of the atoms in most oxide glasses are oxygens. An alternative approach involves post-treatment of the glass.

Probing the Catalytic Activity of Sulfate-Derived Pristine and Post-Treated Porous TiO(101) Anatase Mesocrystals by the Oxidative Desulfurization of Dibenzothiophenes.

Mesocrystals (basically nanostructures showing alignment of nanocrystals well beyond crystal size) are attracting considerable attention for modeling and optimization of functionalities. However, for surface-driven applications (heterogeneous catalysis), only those mesocrystals with excellent textural properties are expected to fulfill their potential. This is especially true for oxidative desulfuration of dibenzothiophenes (hard to desulfurize organosulfur compounds found in fossil fuels).

Charge stabilizing tris(triphenylamine)-zinc porphyrin-carbon nanotube hybrids: synthesis, characterization and excited state charge transfer studies.

Functionalization of single-walled (SWCNTs) and double-walled carbon nanotubes (DWCNTs) with a charge stabilizing zinc porphyrin functionalized with triphenylamine entities has been accomplished. The synthetic approach involved the reaction of tris-(triphenylamine)porphyrinato zinc(ii) with iodobenzene functionalized nanotubes through a Sonogashira C-C cross coupling reaction under microwave irradiation conditions. Evidence of covalent functionalization and the extent of functionalization was obtained from systematic studies carried out by AFM, TGA, XPS and Raman spectroscopy techniques.

Effect of water-DNA interactions on elastic properties of DNA self-assembled monolayers.

DNA-water interactions have revealed as very important actor in DNA mechanics, from the molecular to the macroscopic scale. Given the particularly useful properties of DNA molecules to engineer novel materials through self-assembly and by bridging organic and inorganic materials, the interest in understanding DNA elasticity has crossed the boundaries of life science to reach also materials science and engineering. Here we show that thin films of DNA constructed through the self-assembly of sulfur tethered ssDNA strands demonstrate a Young's modulus tuning range of about 10 GPa by simply varying the environment relative humidity from 0% up to 70%.

A decacobalt(ii) cluster with triple-sandwich structure obtained by partial reductive hydrolysis of a pentacobalt(ii/iii) Weakley-type polyoxometalate.

Partial reductive hydrolysis of a penta-Co cluster [Co(HO)(CoWO)(PWO)] (1) leads to the formation of [Co{Co(HO)(Co(OH)WO)(PWO)}] (2). This polyoxometalate is made up of two capping [PWO] units and two bridging [WO] units that assemble to encapsulate a novel deca-Co cluster core comprising octahedral and tetrahedral Co ions.

Modulation of the exfoliated graphene work function through cycloaddition of nitrile imines.

After the feasibility of the 1,3-dipolar cycloaddition reaction between nitrile imines and exfoliated graphene by density functional theory calculations was proved, very few-layer graphene was effectively functionalized using this procedure. Hydrazones with different electronic properties were used as precursors for the 1,3-dipoles, and microwave irradiation as an energy source enabled the reaction to be performed in a few minutes. The anchoring of organic addends on the graphene surface was confirmed by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis.

Ga-Promoted Photocatalytic H2 Production over Pt/ZnO Nanostructures.

Photocatalytic H2 generation is investigated over a series of Ga-modified ZnO photocatalysts that were prepared by hydrothermal methods. It is found that the structural, textural, and optoelectronic properties remarkably depend on the Ga content. The photocatalytic activity is higher in samples with Ga content equal to or lower than 5.

Ultrafast electron transfer in all-carbon-based SWCNT-C60 donor-acceptor nanoensembles connected by poly(phenylene-ethynylene) spacers.

Building all-carbon based functional materials for light energy harvesting applications could be a solution to tackle and reduce environmental carbon output. However, development of such all-carbon based donor-acceptor hybrids and demonstration of photoinduced charge separation in such nanohybrids is a challenge since in these hybrids part of the carbon material should act as an electron donating or accepting photosensitizer while the second part should fulfil the role of an electron acceptor or donor. In the present work, we have successfully addressed this issue by synthesizing covalently linked all-carbon-based donor-acceptor nanoensembles using single-walled carbon nanotubes (SWCNTs) as the donor and C60 as the acceptor.

Triazine-Carbon Nanotubes: New Platforms for the Design of Flavin Receptors.

The synthesis of functionalised carbon nanotubes as receptors for riboflavin (RBF) is reported. Carbon nanotubes, both single-walled and multi-walled, have been functionalised with 1,3,5-triazines and p-tolyl chains by aryl radical addition under microwave irradiation and the derivatives have been fully characterised by using a range of techniques. The interactions between riboflavin and the hybrids were analysed by using fluorescence and UV/Vis spectroscopic techniques.

From Nanorods to Nanowires of CdS Synthesized by a Solvothermal Method: Influence of the Morphology on the Photoactivity for Hydrogen Evolution from Water.

The effect of temperature and water/thiourea ratio on the growth, crystallinity and morphological characteristics of CdS nanostructures synthetized by a solvothermal method using ethylenediamine as solvent were studied. The temperature and water/thiourea ratio used in the synthesis determine the surface area, shape, length and degree of crystallinity of the CdS nanostructures obtained. Nanowires of high crystallinity and length were obtained when the solvothermal synthesis was performed at 190 °C, while nanorods with lower length and crystallinity were obtained as the solvothermal temperature decreased to 120 °C.

Self-Assembly of 1D/2D Hybrid Nanostructures Consisting of a Cd(II) Coordination Polymer and NiAl-Layered Double Hydroxides.

The preparation and characterization of a novel hybrid material based on the combination of a 2D-layered double hydroxide (LDH) nanosheets and a 1D-coordination polymer (1D-CP) has been achieved through a simple mixture of suspensions of both building blocks via an exfoliation/restacking approach. The hybrid material has been thoroughly characterized demonstrating that the 1D-CP moieties are intercalated as well as adsorbed on the surface of the LDH, giving rise to a layered assembly with the coexistence of the functionalities of their initial constituents. This hybrid represents the first example of the assembly of 1D/2D nanomaterials combining LDH with CP and opens the door for a plethora of different functional hybrid systems.