Electro-catalytically active Au@Pt nanoparticles for hydrogen evolution reaction: an insight into a tryptophan mediated supramolecular interface towards a universal core–shell synthesis approach

RSC Advances ◽  
2014 ◽  
Vol 4 (89) ◽  
pp. 48458-48464 ◽  
Author(s):  
Sarvesh Kumar Srivastava ◽  
Jonathan Sabaté del Río ◽  
Ciara K. O'Sullivan ◽  
Chiaki Ogino ◽  
Akihiko Kondo
Keyword(s):  
Room Temperature ◽  
Bimetallic Nanoparticles ◽  
Pt Nanoparticles ◽  
Aqueous Environment ◽  
Rapid Synthesis ◽  
One Pot ◽  
Temperature Method ◽  
Catalytically Active ◽  
Synthesis Approach ◽  
Insight Into

We report an eco-friendly, one-pot, room-temperature method for the rapid synthesis of electrocatalytically active Au@Pt (50 nm) bimetallic nanoparticles via tryptophan (Trp) induced interface in an aqueous environment.

ChemInform Abstract: Metal-Free, One-Pot, Rapid Synthesis of Tetrahydropyridines Using Acetic Acid as Solvent and Catalyst at Room Temperature

ChemInform ◽  
2014 ◽  
Vol 45 (33) ◽  
pp. no-no
Author(s):  
Umamahesh Balijapalli ◽  
Sathishkumar Munusamy ◽  
Karthikeyan Natesan Sundaramoorthy ◽  
Sathiyanarayanan Kulathu Iyer
Keyword(s):  
Acetic Acid ◽  
Room Temperature ◽  
Rapid Synthesis ◽  
One Pot ◽  
Metal Free

Insight into growth of Au–Pt bimetallic nanoparticles: anin situXAS study

2017 ◽  
Vol 24 (4) ◽  
pp. 825-835 ◽  
Author(s):  
Chandrani Nayak ◽  
D. Bhattacharyya ◽  
K. Bhattacharyya ◽  
A. K. Tripathi ◽  
R. D. Bapat ◽  
...  
Keyword(s):  
Bimetallic Nanoparticles ◽  
Energy Dispersive ◽  
Core Shell ◽  
One Pot ◽  
X Ray ◽  
The Core ◽  
One Pot Synthesis ◽  
X Ray Absorption ◽  
Insight Into

Au–Pt bimetallic nanoparticles have been synthesized through a one-pot synthesis route from their respective chloride precursors using block copolymer as a stabilizer. Growth of the nanoparticles has been studied by simultaneousin situmeasurement of X-ray absorption spectroscopy (XAS) and UV–Vis spectroscopy at the energy-dispersive EXAFS beamline (BL-08) at Indus-2 SRS at RRCAT, Indore, India.In situXAS spectra, comprising both X-ray near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS) parts, have been measured simultaneously at the Au and PtL3-edges. While the XANES spectra of the precursors provide real-time information on the reduction process, the EXAFS spectra reveal the structure of the clusters formed in the intermediate stages of growth. This insight into the formation process throws light on how the difference in the reduction potential of the two precursors could be used to obtain the core–shell-type configuration of a bimetallic alloy in a one-pot synthesis method. The core–shell-type structure of the nanoparticles has also been confirmed byex situenergy-dispersive spectroscopy line-scan and X-ray photoelectron spectroscopy measurements within situion etching on fully formed nanoparticles.

scholarly journals Metal-Free, One-Pot, Rapid Synthesis of Tetrahydropyridines Using Acetic Acid as Solvent and Catalyst at Room Temperature

2014 ◽  
Vol 44 (7) ◽  
pp. 943-953 ◽  
Author(s):  
Umamahesh Balijapalli ◽  
Sathishkumar Munusamy ◽  
Karthikeyan Natesan Sundaramoorthy ◽  
Sathiyanarayanan Kulathu Iyer
Keyword(s):  
Acetic Acid ◽  
Room Temperature ◽  
Rapid Synthesis ◽  
One Pot ◽  
Metal Free

scholarly journals A general synthesis approach for supported bimetallic nanoparticles via surface inorganometallic chemistry

Science ◽  
2018 ◽  
Vol 362 (6414) ◽  
pp. 560-564 ◽  
Author(s):  
Kunlun Ding ◽  
David A. Cullen ◽  
Laibao Zhang ◽  
Zhi Cao ◽  
Amitava D. Roy ◽  
...  
Keyword(s):  
Bimetallic Nanoparticles ◽  
Pt Nanoparticles ◽  
Catalytic Performance ◽  
Double Complex ◽  
Silica Substrate ◽  
Sequential Adsorption ◽  
Complex Salts ◽  
Acetylene Selective Hydrogenation ◽  
General Synthesis ◽  
Synthesis Approach

The synthesis of ultrasmall supported bimetallic nanoparticles (between 1 and 3 nanometers in diameter) with well-defined stoichiometry and intimacy between constituent metals remains a substantial challenge. We synthesized 10 different supported bimetallic nanoparticles via surface inorganometallic chemistry by decomposing and reducing surface-adsorbed heterometallic double complex salts, which are readily obtained upon sequential adsorption of target cations and anions on a silica substrate. For example, adsorption of tetraamminepalladium(II) [Pd(NH3)42+] followed by adsorption of tetrachloroplatinate [PtCl42−] was used to form palladium-platinum (Pd-Pt) nanoparticles. These supported bimetallic nanoparticles show enhanced catalytic performance in acetylene selective hydrogenation, which clearly demonstrates a synergistic effect between constituent metals.

scholarly journals The Use of a Biopolymer Conjugate for an Eco-Friendly One-Pot Synthesis of Palladium-Platinum Alloys

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1948 ◽  
Author(s):  
Daniele Silvestri ◽  
Stanisław Wacławek ◽  
Rohith K. Ramakrishnan ◽  
Abhilash Venkateshaiah ◽  
Kamil Krawczyk ◽  
...  
Keyword(s):  
Green Synthesis ◽  
Bimetallic Nanoparticles ◽  
Catalytic Reduction ◽  
Pt Nanoparticles ◽  
Attenuated Total Reflection ◽  
Molar Ratio ◽  
One Pot ◽  
Synthesis Conditions ◽  
Molar Ratios ◽  
Green Approach

Raising health and environmental concerns over the nanoparticles synthesized from hazardous chemicals have urged researchers to focus on safer, environmentally friendlier and cheaper alternatives as well as prompted the development of green synthesis. Apart from many advantages, green synthesis is often not selective enough (among other issues) to create shape-specific nanoparticle structures. Herein, we have used a biopolymer conjugate and Pd and Pt precursors to prepare sustainable bimetallic nanoparticles with various morphology types. The nanoparticles were synthesized by a novel green approach using a bio-conjugate of chitosan and polyhydroxybutyrate (Cs-PHB). The bio-conjugate plays the simultaneous roles of a reducing and a capping agent, which was confirmed by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and energy dispersive X-ray spectrometry (EDS) analysis, proving the presence of a Cs-PHB layer on the surface of the prepared nanoparticles. The EDS profile also revealed the elemental structure of these nanoparticles and confirmed the formation of a Pd/Pt alloy. TEM morphological analysis showed the formation of star-like, octahedron or decahedron Pd/Pt nanoparticles, depending on the synthesis conditions. The bimetallic Pd/Pt nanoparticles synthesized with various Pd/Pt molar ratios were successfully applied for the catalytic reduction of 4-nitrophenol to 4-aminophenol by borohydride. The calculated κc values (ratio of kapp to the concentration of the catalyst) revealed that the decahedron nanoparticles (size of 15 ± 4 nm), synthesized at the molar ratio of 2:1 (Pd/Pt), temperature of 130 °C, 10 g/L of Cs-PHB conjugate and time of 30 min, exhibited excellent catalytic activity compared to other bimetallic nanoparticles reported in the literature.

Green synthesis of mixed metallic nanoparticles using room temperature self-assembly

2017 ◽  
Vol 13 (2) ◽  
pp. 4671-4677 ◽  
Author(s):  
A. M. Abdelghany ◽  
A.H. Oraby ◽  
Awatif A Hindi ◽  
Doaa M El-Nagar ◽  
Fathia S Alhakami
Keyword(s):  
Self Assembly ◽  
Metallic Nanoparticles ◽  
Room Temperature ◽  
Bimetallic Nanoparticles ◽  
Reduction Process ◽  
Nano Particles ◽  
Nano Structure ◽  
Small Shift ◽  
Molar Ratios ◽  
Vis Spectroscopy

Bimetallic nanoparticles of silver (Ag) and gold (Au) were synthesized at room temperature using Curcumin. Reduction process of silver and gold ions with different molar ratios leads to production of different nanostructures including alloys and core-shells. Produced nanoparticles were characterized simultaneously with FTIR, UV/vis. spectroscopy, transmission electron microscopy (TEM), and Energy-dispersive X-ray (EDAX). UV/vis. optical absorption spectra of as synthesized nanoparticles reveals presence of surface palsmon resonance (SPR) of both silver at (425 nm) and gold at (540 nm) with small shift and broadness of gold band after mixing with resucing and capping agent in natural extract which suggest presence of bimetallic nano structure (Au/Ag). FTIR and EDAX data approve the presence of bimetallic nano structure combined with curcumin extract. TEM micrographs shows that silver and gold can be synthesized separately in the form of nano particles using curcumin extract. Synthesis of gold nano particles in presence of silver effectively enhance and control formation of bi-metallic structure.

Room Temperature Alkali Metal Reduction of Carbon Dioxide

2020 ◽  
Author(s):  
Lucas A. Freeman ◽  
Akachukwu D. Obi ◽  
Haleigh R. Machost ◽  
Andrew Molino ◽  
Asa W. Nichols ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Alkali Metals ◽  
Room Temperature ◽  
Chemical Reduction ◽  
Bond Cleavage ◽  
Open Shell ◽  
Metal Reduction ◽  
One Pot ◽  
Earth Abundant ◽  
Electron Reduction

The reduction of the relatively inert carbon–oxygen bonds of CO<sub>2</sub> to access useful CO<sub>2</sub>-derived organic products is one of the most important fundamental challenges in synthetic chemistry. Facilitating this bond-cleavage using earth-abundant, non-toxic main group elements (MGEs) is especially arduous because of the difficulty in achieving strong inner-sphere interactions between CO<sub>2</sub> and the MGE. Herein we report the first successful chemical reduction of CO<sub>2</sub> at room temperature by alkali metals, promoted by a cyclic(alkyl)(amino) carbene (CAAC). One-electron reduction of CAAC-CO<sub>2</sub> adduct (<b>1</b>) with lithium, sodium or potassium metal yields stable monoanionic radicals clusters [M(CAAC–CO<sub>2</sub>)]<sub>n</sub>(M = Li, Na, K, <b> 2</b>-<b>4</b>) and two-electron alkali metal reduction affords open-shell, dianionic clusters of the general formula [M<sub>2</sub>(CAAC–CO<sub>2</sub>)]<sub>n </sub>(<b>5</b>-<b>8</b>). It is notable that these crystalline clusters of reduced CO<sub>2</sub> may also be isolated via the “one-pot” reaction of free CO<sub>2</sub> with free CAAC followed by the addition of alkali metals – a reductive process which does not occur in the absence of carbene. Each of the products <b>2</b>-<b>8</b> were investigated using a combination of experimental and theoretical methods.<br>

A Series of Metal-Organic Frameworks for Selective CO2 Capture and Catalytic Oxidative Carboxylation of Olefins

2018 ◽  
Author(s):  
Huong T. D. Nguyen ◽  
Y B. N. Tran ◽  
Hung N. Nguyen ◽  
Tranh C. Nguyen ◽  
Felipe Gándara ◽  
...  
Keyword(s):  
Room Temperature ◽  
Gas Adsorption ◽  
New Materials ◽  
One Pot ◽  
Acid Gas ◽  
Naphthalene Diimide ◽  
Styrene Carbonate ◽  
Metal Organic ◽  
Adsorption Of Co ◽  
The One

<p>Three novel lanthanide metal˗organic frameworks (Ln-MOFs), namely MOF-590, -591, and -592 were constructed from a naphthalene diimide tetracarboxylic acid. Gas adsorption measurements of MOF-591 and -592 revealed good adsorption of CO<sub>2</sub> (low pressure, at room temperature) and moderate CO<sub>2</sub> selectivity over N<sub>2</sub> and CH<sub>4</sub>. Accordingly, breakthrough measurements were performed on a representative MOF-592, in which the separation of CO<sub>2</sub> from binary mixture containing N<sub>2</sub> and CO<sub>2</sub> was demonstrated without any loss in performance over three consecutive cycles. Moreover, MOF-590, MOF-591, and MOF-592 exhibited catalytic activity in the one-pot synthesis of styrene carbonate from styrene and CO<sub>2</sub> under mild conditions (1 atm CO<sub>2</sub>, 80 °C, and solvent-free). Among the new materials, MOF-590 revealed a remarkable efficiency with exceptional conversion (96%), selectivity (95%), and yield (91%). </p><br>

Sewage sludge as a precursor of adsorbents/catalysts for environmental applications

2007 ◽  
Vol 2 (1) ◽  
Author(s):  
A. Ros ◽  
C. Canals-Batlle ◽  
M.A. Lillo-Ródenas ◽  
E. Fuente ◽  
M. A. Montes-Morán ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Room Temperature ◽  
Waste Water Treatment ◽  
Textural Properties ◽  
Active Species ◽  
Elemental Sulphur ◽  
Gaseous Emissions ◽  
Removal Experiments ◽  
Catalytically Active

This paper focuses on the valorisation of solid residues obtained from the thermal treatment of sewage sludge. In particular, sewage sludge samples were collected from two waste water treatment plants (WWTPs) with different sludge line basic operations. After drying, sludges were heated up to 700 °C in appropriate ovens under diluted air (gasification) and inert (pyrolysis) atmospheres. The solids obtained, as well as the dried (raw) sludges, were characterised to determine their textural properties and chemical composition, including the speciation of their inorganic fraction. All the materials under study were employed as adsorbents/catalysts in H2S removal experiments at room temperature. It was found that, depending on the particular sludge characteristics, outstanding results can be achieved both in terms of retention capacities and selectivity. Some of the solids outperform commercially available sorbents specially designed for gaseous emissions control. In these adsorbents/catalysts, H2S is selectively oxidised to elemental sulphur most likely due to the presence of inorganic, catalytically active species. The role of the carbon-enriched part on these solids is also remarked.

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