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Nano Catalyst

Shinji Sugihara, Masahiro Sudo, Yasushi Maeda
Biomimetic ABC triblock copolymers of poly[2-(methacryloyloxy)ethyl phosphorylcholine]- b-poly[2-(dimethylamino)ethyl methacrylate]- b-poly(2-hydroxypropyl methacrylate) (PMPC- b-PDMA- b-PHPMA) were synthesized by RAFT aqueous dispersion polymerization of 2-hydroxypropyl methacrylate (HPMA) in the presence of a PMPC- b-PDMA macromolecular chain transfer agent (macro-CTA). This ABC triblock copolymer deploys well-known biocompatible PMPC and PDMA for the coordination of Ag+ ions to form silver nanoparticles in situ on reduction, and PHPMA for assembling (core) in water...
August 15, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Tie Liu, Xiuhui Zhang, Tao Huang, Aishui Yu
The rational design and synthetic route to fabricate hybrid materials with desirable electrocatalytic functionalities remain critical but still challenging for sustainable energy devices. Here, we constructed a tungsten trioxide nano-lamellae chemically anchored with pyridinic-N-dominated doped CNT/graphene frameworks (W-NCG) via a general solution-based synthesis method. The detailed results indicated that this hybrid structure is composed of vacancy-defect abundant WO3 porous nanoflakes anchoring through or onto a 3D N-doped carbon matrix...
August 10, 2018: Nanoscale
Yukun Xiao, Zhihua Cheng, Yang Zhao, Liangti Qu
The rational design of an efficient and robust oxygen reduction reaction (ORR) electrocatalyst is vital for energy conversion and storage systems, especially for metal-air batteries. Herein, we report a highly nanocrumpled and nitrogen, phosphorus-codoped nanocarbon (NC-NPC) synthesized by direct pyrolysis of melamine and triphenylphosphine. With the rich nano-crumpled structure and codoping of heteroatoms, this low-cost catalyst exhibits an excellent ORR performance, and possesses a half-wave potential of 0...
August 9, 2018: Nanoscale
Fatemeh Kiani, Hossein Naeimi
A novel, green and rapid sonochemical research to preparation of the biphenyls was carried out through the coupling reaction between various aryl halides and phenylboronic acid by using bis(propyl malononitrile) Ni (0) complex (NiFe2 O4 @SiO2 -BPMN-Ni) as an efficient nano catalyst. The catalyst can be recycled via an external magnet and reused several times without considerable loss of its catalytic activity. Compare to the previous works, this procedure has advantages such as easy workup, high yields of products, environmentally benign and short reaction times...
November 2018: Ultrasonics Sonochemistry
Polykarpos A Lazaridis, Apostolos P Fotopoulos, Stamatia A Karakoulia, Konstantinos S Triantafyllidis
The valorization of lignin that derives as by product in various biomass conversion processes has become a major research and technological objective. The potential of the production of valuable mono-aromatics (BTX and others) and (alkyl)phenols by catalytic fast pyrolysis of lignin is investigated in this work by the use of ZSM-5 zeolites with different acidic and porosity characteristics. More specifically, conventional microporous ZSM-5 (Si/Al = 11.5, 25, 40), nano-sized (≤20 nm, by direct synthesis) and mesoporous (9 nm, by mild alkaline treatment) ZSM-5 zeolites were tested in the fast pyrolysis of a softwood kraft lignin at 400-600°C on a Py/GC-MS system and a fixed-bed reactor unit...
2018: Frontiers in Chemistry
Sarah Schmidt-Dannert, Guoqiang Zhang, Timothy Johnston, Maureen B Quin, Claudia Schmidt-Dannert
Biological materials that are genetically encoded and can self-assemble offer great potential as immobilization platforms in industrial biocatalysis. Protein-based scaffolds can be used for the spatial organization of enzymes, to stabilize the catalysts and provide optimal microenvironments for reaction sequences. In our previous work, we created a protein scaffold for enzyme localization by engineering the bacterial microcompartment shell protein EutM from Salmonella enterica. Here, we sought to expand this work by developing a toolbox of EutM proteins with different properties, with the potential to be used for future immobilization of enzymes...
July 31, 2018: Applied Microbiology and Biotechnology
G S Hikku, K Jeyasubramanian, J Jacobjose, P Thiruramanathan, Pandiyarasan Veluswamy, Hiroya Ikeda
Herein, we reported the photo-catalytic degradation/anti-bacterial property of Ag-doped ZnO nanoparticles (SDZO Nps) prepared by a facile gel-combustion technique and its self-cleaning/self-refreshing/self-disinfectant behaviour while on impregnating as pigment into the alkyd resin based coating. The influence of doping Ag (1% & 2%) with ZnO has been evaluated in terms of crystal structure, morphology, optical properties, etc. using X-ray diffraction analysis, Field Emission Scanning Electron Microscope, UV-Vis analysis, and Photoluminescence spectra...
July 21, 2018: Journal of Colloid and Interface Science
Alexey S Kashin, Evgeniya S Degtyareva, Dmitry B Eremin, Valentine P Ananikov
The great impact of the nanoscale organization of reactive species on their performance in chemical transformations creates the possibility of fine-tuning of reaction parameters by modulating the nano-level properties. This methodology is extensively applied for the catalysts development whereas nanostructured reactants represent the practically unexplored area. Here we report the palladium- and copper-catalyzed cross-coupling reaction involving nano-structured nickel thiolate particles as reagents. On the basis of experimental findings we propose the cooperative effect of nano-level and molecular-level properties on their reactivity...
July 26, 2018: Nature Communications
Shinobu Takao, Oki Sekizawa, Gabor Samjeské, Takuma Kaneko, Kotaro Higashi, Yusuke Yoshida, Xiao Zhao, Tomohiro Sakata, Takashi Yamamoto, Takao Gunji, Tomoya Uruga, Yasuhiro Iwasawa
It is hard to directly visualize spectroscopic and atomic‒nanoscopic information on the degraded Pt/C cathode layer inside polymer electrolyte fuel cell (PEFC). However, it is mandatory to understand the preferential area, sequence and relationship of the degradations of Pt nanoparticles and carbon support in the Pt/C cathode layer by directly observing the Pt/C cathode catalyst for development of next-generation PEFC cathode catalysts. Here, the spectroscopic, chemical and morphological visualization of the degradation of Pt/C cathode electrocatalysts in PEFC was performed successfully by a same-view combination technique of nano-XAFS and TEM/STEM-EDS under a humid N2 atmosphere...
July 25, 2018: ACS Applied Materials & Interfaces
Antonio Delgado-Gonzalez, Emilio Garcia-Fernandez, Teresa Valero, M Victoria Cano-Cortes, Maria J Ruedas-Rama, Asier Unciti-Broceta, Rosario M Sanchez-Martin, Juan J Diaz-Mochon, Angel Orte
Herein, we describe the synthesis and application of cross-linked polystyrene-based dual-function nano- and microparticles containing both fluorescent tags and metals. Despite containing a single dye, these particles exhibit a characteristic dual-band fluorescence emission. Moreover, these particles can be combined with different metal ions to obtain hybrid metallofluorescent particles. We demonstrate that these particles are easily nanofected into living cells, allowing them to be used for effective fingerprinting in multimodal fluorescence-based and mass spectrometry-based flow cytometry experiments...
January 31, 2018: ACS Omega
Robert K Adamik, Naiara Hernández-Ibáñez, Jesus Iniesta, Jennifer K Edwards, Alexander G R Howe, Robert D Armstrong, Stuart H Taylor, Alberto Roldan, Yuanyang Rong, Richard Malpass-Evans, Mariolino Carta, Neil B McKeown, Daping He, Frank Marken
The one-step vacuum carbonization synthesis of a platinum nano-catalyst embedded in a microporous heterocarbon (Pt@cPIM) is demonstrated. A nitrogen-rich polymer of an intrinsic microporosity (PIM) precursor is impregnated with PtCl₆2- to give (after vacuum carbonization at 700 °C) a nitrogen-containing heterocarbon with embedded Pt nanoparticles of typically 1⁻4 nm diameter (with some particles up to 20 nm diameter). The Brunauer-Emmett-Teller (BET) surface area of this hybrid material is 518 m² g-1 (with a cumulative pore volume of 1...
July 18, 2018: Nanomaterials
Sung-Yup Kim, Hong Woo Lee, Sung Jin Pai, Sang Soo Han
We report a molecular dynamics (MD) simulation employing the reactive force field (ReaxFF), developed from various first-principles calculations in this study, on ammonia (NH3 ) synthesis from nitrogen (N2 ) and hydrogen (H2 ) gases over Ru nanoparticle (NP) catalysts. Using ReaxFF-MD simulations, we predict not only the activities and selectivities but also the durabilities of the nanocatalysts and discuss the size effect and process conditions (temperature and pressure). Among the NPs (diameter = 3, 4, 5, and 10 nm) considered in this study, the 4 nm NPs show the highest activity, in contrast to our intuition that the smallest NP should provide the highest activity, as it has the highest surface area...
August 8, 2018: ACS Applied Materials & Interfaces
Mengbin Gu, Qian Sui, Usman Farooq, Xiang Zhang, Zhaofu Qiu, Shuguang Lyu
Nano zero-valent iron (nZVI) particles with higher reactivity have been recognized as more efficient catalysts than Fe(II) for the groundwater remediation. The rapid emergence of novel catalyst supports efficiently prevent the rapid aggregation of nZVI and further improve catalytic reactivity. However, the lack of ability to avoid the potential oxidation of bare nZVI-support structure in air environment hinders its wider application in the actual contaminated sites. In this study, nZVI on reduced graphene oxide (rGO) functionalized by polydopamine (PDA) (nZVI-PDA@rGO) was synthesized successfully and applied into sodium persulfate (SPS), potassium monopersulfate (PMS) and H2 O2 oxidative environments to remove trichloroethylene (TCE)...
July 9, 2018: Journal of Hazardous Materials
Jie Gao, Qian Jiang, Yuefeng Liu, Wei Liu, Wei Chu, Dang Sheng Su
Oxygenated functionalized carbon nanotube (oCNT) supported LaOx -promoted Ni nanoparticles (10Ni-xLa/oCNT) were prepared by the co-impregnation method and tested for synthetic natural gas from the CO2 reduction reaction. Several advanced characterization methods, including atomic resolution scanning transmission electron microscopy (STEM), temperature programmed experiments (TPSR, CO2 -TPD, and H2 -TPR) and X-ray photoelectron spectroscopy (XPS), were applied to explore, for the first time, the origin of structure modulation of LaOx species on oCNT supported Ni-LaOx hybrids and the structure-activity relationship over the CO2 reduction reaction...
August 7, 2018: Nanoscale
Kamel Shoueir, Hamdy El-Sheshtawy, Mohammed Misbah, Hamza El-Hosainy, Ibrahim El-Mehasseb, Maged El-Kemary
High efficient 3,5-Dinitrosalicylic acid/Chitosan/MnFe2 O4 (DNSA@CS@MnFe2 O4 ) nano photocatalyst was prepared to enrich both adsorption and photodecomposition under visible light. This paper focused on the importance of DNSA@CS as an excellent connector between methylene blue (MB) and MnFe2 O4 for accelerating photodegradation with the encouragement of photo-Fenton catalytic reagent hydrogen peroxide (H2 O2 ). The optimum conditions were: contact time, 30 min, H2 O2 concentration, 0.16 M, pH factor 9 and dosage 0...
October 1, 2018: Carbohydrate Polymers
Yaqing Yin, Tingting Liu, Dan Liu, Zhao Wang, Qibo Deng, Deyu Qu, Zhizhong Xie, Haolin Tang, Junsheng Li
Despite recent progress in the development of earth abundant electrochemical catalyst for hydrogen evolution reaction (HER), Pt based materials still stand as the state of the art HER catalyst. Due to the high cost of Pt, it is desirable to increase the utilization efficiency of Pt in practical HER process to a realize cost effective hydrogen production. Herein, we repot a novel nitrogen doped ordered mesoporous carbon supported Pt (Pt@NOMC-A) catalyst with a low Pt loading of 7.2 wt% and show that the synergy between Pt nanoparticles and carbon support, as well as the physical confinement offered by the carbon support enhance the electrochemical performance of the novel catalyst...
June 30, 2018: Journal of Colloid and Interface Science
Rajinder Singh, Manesh Kumar, Heena Khajuria, Jigmet Ladol, Haq Nawaz Sheikh
A facile one step solvothermal method is designed for the synthesis of visible light-sensitive ZnO-nitrogen doped graphene (ZNG) nano photocatalysts using ethylene glycol as a solvent as well as an agent to prevent aggregation of graphene layers. The deposition of ZnO nanoparticles onto the NG layers was confirmed by high resolution transmission electron microscope (HR-TEM), scanning electron microscope (SEM), powder X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). UV-Vis spectroscopy (UV-Vis) was used to study the enhanced photocatalytic activity, which shows the red-shift of the band-edge as compared to ZnO nano particles...
June 2018: Acta Chimica Slovenica
Arindam Indra, Taeseup Song, Ungyu Paik
Exploring new materials with high efficiency and durability is the major requirement in the field of sustainable energy conversion and storage systems. Numerous techniques have been developed in last three decades to enhance the efficiency of the catalyst systems, control over the composition, structure, surface area, pore size, and moreover morphology of the particles. In this respect, metal organic framework (MOF) derived catalysts are emerged as the finest materials with tunable properties and activities for the energy conversion and storage...
July 8, 2018: Advanced Materials
Rafael Müller, Ilya Kuznetsov, Yunieski Arbelo, Matthias Trottmann, Carmen S Menoni, Jorge J Rocca, Greta R Patzke, Davide Bleiner
Nanoscale depth profiling analysis of a CoNCN-coated electrode for water oxidation catalysis was carried out using table-top extreme ultraviolet (XUV) laser ablation time-of-flight mass spectrometry. The self-developed laser operates at λ = 46.9 nm and represents factor of 4 reduction in wavelength with respect to the 193 nm excimer laser. The reduction of the wavelength is an alternative approach to the reduction of the pulse duration, to enhance the ablation characteristics and obtain smaller quasi-nondestructive ablation pits...
July 13, 2018: Analytical Chemistry
Miguel Solsona, Anne-Eva Nieuwelink, Florian Meirer, Leon Abelmann, Mathieu Odijk, Wouter Olthuis, Bert M Weckhuysen, Albert van den Berg
A better understanding of the deactivation processes taking place within solid catalysts is vital to design better ones. However, since inter-particle heterogeneities are more a rule than an exception, particle sorting is crucial to analyse single catalyst particles in detail. Microfluidics offers new possibilities to sort catalysts at the single particle level. Herein, we report a first-of-its-kind 3D printed magnetophoretic chip able to sort catalyst particles by their magnetic moment. Fluid catalytic cracking (FCC) particles were separated based on their Fe content...
July 1, 2018: Angewandte Chemie
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