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.

scholarly journals A green approach to the synthesis of a nano catalyst and the role of basicity, calcination, catalytic activity and aging in the green synthesis of 2-aryl bezimidazoles, benzothiazoles and benzoxazoles

RSC Advances ◽  
2017 ◽  
Vol 7 (67) ◽  
pp. 42000-42012 ◽  
Author(s):  
Pramod K. Sahu
Keyword(s):  
Catalytic Activity ◽  
Green Synthesis ◽  
Room Temperature ◽  
Molar Ratios ◽  
Green Approach ◽  
Grinding Method ◽  
Nano Catalyst ◽  
Layered Catalyst

A green synthesis of hydrotalcite (a double layered catalyst) by a grinding method using Al/Mg molar ratios of 1.0–3.0 at room temperature is described.

A one-pot route to the synthesis of alloyed Cu/Ag bimetallic nanoparticles with different mass ratios for catalytic reduction of 4-nitrophenol

2015 ◽  
Vol 3 (7) ◽  
pp. 3450-3455 ◽  
Author(s):  
Wei Wu ◽  
Mei Lei ◽  
Shuanglei Yang ◽  
Li Zhou ◽  
Li Liu ◽  
...  
Keyword(s):  
Bimetallic Catalysts ◽  
High Performance ◽  
Bimetallic Nanoparticles ◽  
Catalytic Reduction ◽  
Low Cost ◽  
Industrial Applications ◽  
Research Interest ◽  
Alloy Nanoparticles ◽  
One Pot ◽  
Copper Based Alloy

Copper-based alloy nanoparticles (NPs) have recently triggered much research interest for the development of low-cost and high-performance bimetallic catalysts that have industrial applications.

scholarly journals Fabrication of Polypyrrole Nanoparticles Using Microemulsion Polymerization for Diferent Py/APS/SDS Molar Ratios

2016 ◽  
Vol 869 ◽  
pp. 391-395 ◽  
Author(s):  
Ricardo Hidalgo Santim ◽  
Hermes Adolfo de Aquino ◽  
José Antonio Malmonge
Keyword(s):  
Electrical Conductivity ◽  
Near Infrared ◽  
Sodium Dodecylsulfate ◽  
Ammonium Persulfate ◽  
Synthesis Temperature ◽  
Molar Ratio ◽  
Synthesis Conditions ◽  
Molar Ratios ◽  
Nanoparticle Shape ◽  
Polypyrrole Nanoparticles

Polypyrrole nanoparticles (PPy) were synthesized by the chemical oxidative microemulsion of pyrrole (Py) monomer using ammonium persulfate (APS) as an oxidant agent and sodium dodecylsulfate (SDS) as a surfactant at 28°C and 0°C. Different Py:APS:SDS molar ratios were used, and the properties of the resulting material were examined by four-probe DC electrical conductivity, ultraviolet-visible-near infrared (UV-vis-Nir), and Fourier-transform infrared (FTIR) spectroscopies as well as field-emission scanning electron microscopy (FESEM). UV-vis-Nir and FTIR spectra show the formation of a polaron band owing to the doping of PPy by SDS. The electrical conductivity and morphology of PPy nanoparticles depend on the synthesis conditions. Electrical conductivity of ~95.3×10-3 S/cm was achieved for PPy synthesized at 0°C. For the same Py:APS:SDS molar ratio, the nanoparticle shape changed from cylindrical to spherical upon simply lowering the synthesis temperature.

scholarly journals Simple One Pot Preparation of Chemical Hydrogels from Cellulose Dissolved in Cold LiOH/Urea

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 373 ◽  
Author(s):  
Jiayi Yang ◽  
Bruno Medronho ◽  
Björn Lindman ◽  
Magnus Norgren
Keyword(s):  
Molar Ratio ◽  
Cross Linking ◽  
Absorption Properties ◽  
One Pot ◽  
Molar Ratios ◽  
Cellulose Pulp ◽  
Water Uptake Capacity ◽  
Swelling Capacity ◽  
Cellulose Hydrogel ◽  
Water Swelling

In this work, non-derivatized cellulose pulp was dissolved in a cold alkali solution (LiOH/urea) and chemically cross-linked with methylenebisacrylamide (MBA) to form a robust hydrogel with superior water absorption properties. Different cellulose concentrations (i.e., 2, 3 and 4 wt%) and MBA/glucose molar ratios (i.e., 0.26, 0.53 and 1.05) were tested. The cellulose hydrogel cured at 60 °C for 30 min, with a MBA/glucose molar ratio of 1.05, exhibited the highest water swelling capacity absorbing ca. 220 g H2O/g dry hydrogel. Moreover, the data suggest that the cross-linking occurs via a basic Michael addition mechanism. This innovative procedure based on the direct dissolution of unmodified cellulose in LiOH/urea followed by MBA cross-linking provides a simple and fast approach to prepare chemically cross-linked non-derivatized high-molecular-weight cellulose hydrogels with superior water uptake capacity.

scholarly journals One-Pot Synthesis of Al-P-O Catalysts and Their Catalytic Properties for O-Methylation of Catechol and Methanol

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5942
Author(s):  
Dongfei Xu ◽  
Jiaan Ren ◽  
Shengnan Yue ◽  
Xiujing Zou ◽  
Xingfu Shang ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Weak Acid ◽  
Molar Ratio ◽  
Weak Base ◽  
Acid Base ◽  
One Pot ◽  
Catalyst Structure ◽  
Molar Ratios ◽  
One Pot Synthesis ◽  
Catalytic Performances

A series of Al-P-O catalysts (Al-xP-O) were prepared using a P123-assisted one-pot method at different P/Al molar ratios and used for O-methylation of catechol and methanol. The influences of the P/Al molar ratio and P123 addition on catalyst structure and surface acid-base characteristics were investigated in detail. Increasing the P/Al molar ratio more favored crystalline aluminophosphate. The P123-assisted Al3+ and PO43− are known to be stabilized through weak steric force so that the formation of crystalline aluminophosphate could be inhibited at higher P/Al molar ratios. The results showed that the prepared Al-P-O catalysts possessed appropriate weak acid and weak base sites, which was beneficial to the reaction of catechol and methanol. The Al-1.1P-O catalyst synthesized with the assistance of P123 exhibited superior catalytic performances, with 52.5% catechol conversion and higher guaiacol selectivity of 97.6%.

One-pot Preparation of Cu2(OH)3NO3 Nanosheets and Cu(OH)2 Nanowires

2019 ◽  
Vol 9 (4) ◽  
pp. 467-471
Author(s):  
Wenzhe Zhang ◽  
Ailing Yang ◽  
Xichang Bao
Keyword(s):  
Crystal Structures ◽  
Monoclinic Phase ◽  
Orthorhombic Phase ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
One Pot ◽  
Molar Ratios ◽  
Transmission Electron ◽  
Reaction Solution ◽  
Cuo Nanosheets

Introduction: By using Cu(NO3)2 as precursor and polyvinylpyrrolidone (PVP) as surfactant, nanosheets of Cu2(OH)3NO3, nanowires of Cu(OH)2 or the mixture of the two were prepared under different molar ratios of OH− to Cu2+. Materials and Methods: The crystal structures and morphologies of the products were characterized by X-Ray Diffraction (XRD) and Transmission Electron Microscope (TEM). Results: When the molar ratio of OH− to Cu2+ in reaction solution is lower than 1.28, pure Cu2(OH)3NO3 nanosheets were obtained. The thickness of one piece of nanosheet is about 167 nm. The Cu2(OH)3NO3 nanosheets consists of two types of crystal structures, monoclinic phase and orthorhombic phase. With increase of the molar ratio of OH− to Cu2+, the monoclinic phase of Cu2(OH)3NO3 was transferred to the orthorhombic phase of Cu2(OH)3NO3. When the molar ratio of OH− to Cu2+ is within 1.28-2.24, the product is the mixture of Cu2(OH)3NO3 nanosheets and Cu(OH)2 nanowires. And when this molar ratio is higher than 2.24, only Cu(OH)2 nanowires were produced. The lengths and the diameters of the Cu(OH)2 nanowires are in the region of 50-250 nm and 10 nm, respectively. Conclusion: The reason of the Cu2(OH)3NO3 nanosheets changing into the Cu(OH)2 nanowires is that the OH− anions replace the NO3 − anions in the layered Cu2(OH)3NO3 nanosheets, which causes the rupture of hydrogen bonds connecting the adjacent layers. The Cu(OH)2 nanowires were not stable and found to become spindled CuO nanosheets in air at room temperature.

Green synthesis of Pt–Pd bimetallic nanoparticle decorated reduced graphene oxide and its robust catalytic activity for efficient ethylene glycol electrooxidation

2018 ◽  
Vol 42 (17) ◽  
pp. 14386-14393 ◽  
Author(s):  
T. Raj kumar ◽  
Dong Jin Yoo ◽  
Ae Rhan Kim ◽  
G. Gnana kumar
Keyword(s):  
Graphene Oxide ◽  
Catalytic Activity ◽  
Ethylene Glycol ◽  
Green Synthesis ◽  
Reduced Graphene Oxide ◽  
Bimetallic Nanoparticles ◽  
One Pot ◽  
Bimetallic Nanoparticle ◽  
Reduced Graphene ◽  
Ethylene Glycol Oxidation

A simple one-pot green synthesis technique is developed to prepare the Pt–Pd bimetallic nanoparticles decorated reduced graphene oxide nanocomposite and its robust catalytic activity for efficient and durable ethylene glycol oxidation is realized.

One-pot green synthesis of bimetallic hollow palladium-platinum nanotubes for enhanced catalytic reduction of p-nitrophenol

2019 ◽  
Vol 539 ◽  
pp. 161-167 ◽  
Author(s):  
Yinan Wang ◽  
Qingchuan Li ◽  
Ping Zhang ◽  
David O'Connor ◽  
Rajender S. Varma ◽  
...  
Keyword(s):  
Green Synthesis ◽  
Catalytic Reduction ◽  
One Pot ◽  
Palladium Platinum
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