scholarly journals A one-step rapid synthesis of TS-1 zeolites with highly catalytically active mononuclear TiO6 species

2020 ◽  
Vol 8 (19) ◽  
pp. 9677-9683 ◽  
Author(s):  
Wenjing Xu ◽  
Tianjun Zhang ◽  
Risheng Bai ◽  
Peng Zhang ◽  
Jihong Yu
Keyword(s):  
Active Sites ◽  
High Performance ◽  
Rational Design ◽  
Heterogeneous Catalysts ◽  
Rapid Synthesis ◽  
Catalytically Active ◽  
One Step

The modulation and determination of the coordination environments of Ti active sites in titanosilicate zeolites are key challenges in the rational design of high-performance heterogeneous catalysts.

scholarly journals Rational design and synthesis of noble-metal nanoframes for catalytic and photonic applications

2016 ◽  
Vol 3 (4) ◽  
pp. 520-533 ◽  
Author(s):  
Xue Wang ◽  
Aleksey Ruditskiy ◽  
Younan Xia
Keyword(s):  
Noble Metal ◽  
Active Sites ◽  
Noble Metals ◽  
Rational Design ◽  
Heterogeneous Catalysts ◽  
Open Architecture ◽  
Design Synthesis ◽  
Design And Synthesis ◽  
Surface Areas ◽  
Catalytically Active

Abstract Nanoframes are unique for their 3D, highly open architecture. When made of noble metals, they are attractive for use as heterogeneous catalysts because of their large specific surface areas, high densities of catalytically active sites and low vulnerability toward sintering. They promise to enhance the catalytic activity and durability while reducing the material loading and cost. For nanoframes composed of Au and/or Ag, they also exhibit highly tunable plasmonic properties similar to those of nanorods. This article presents a brief account of recent progress in the design, synthesis and utilization of noble-metal nanoframes. We start with a discussion of the synthetic strategies, including those involving site-selected deposition and etching, as well as dealloying of both hollow and solid nanocrystals. We then highlight some of the applications enabled by noble-metal nanoframes. Finally, we discuss the challenges and trends with regard to future development.

scholarly journals N, S and Transition-Metal Co-Doped Graphene Nanocomposites as High-Performance Catalyst for Glucose Oxidation in a Direct Glucose Alkaline Fuel Cell

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 202
Author(s):  
Yexin Dai ◽  
Jie Ding ◽  
Jingyu Li ◽  
Yang Li ◽  
Yanping Zong ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Active Sites ◽  
High Performance ◽  
Glucose Oxidation ◽  
Alkaline Fuel Cell ◽  
Blank Group ◽  
Graphene Nanocomposites ◽  
Doped Graphene ◽  
One Step ◽  
Hydrothermal Approach

In this work, reduced graphene oxide (rGO) nanocomposites doped with nitrogen (N), sulfur (S) and transitional metal (Ni, Co, Fe) were synthesized by using a simple one-step in-situ hydrothermal approach. Electrochemical characterization showed that rGO-NS-Ni was the most prominent catalyst for glucose oxidation. The current density of the direct glucose alkaline fuel cell (DGAFC) with rGO-NS-Ni as the anode catalyst reached 148.0 mA/cm2, which was 40.82% higher than the blank group. The DGAFC exhibited a maximum power density of 48 W/m2, which was more than 2.08 folds than that of blank group. The catalyst was further characterized by SEM, XPS and Raman. It was speculated that the boosted performance was due to the synergistic effect of N, S-doped rGO and the metallic redox couples, (Ni2+/Ni3+, Co2+/Co3+ and Fe2+/Fe3+), which created more active sites and accelerated electron transfer. This research can provide insights for the development of environmental benign catalysts and promote the application of the DGAFCs.

scholarly journals Facile Synthesis of Uniform Mesoporous Nb2O5 Micro-Flowers for Enhancing Photodegradation of Methyl Orange

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3783
Author(s):  
Jian-Qing Qiu ◽  
Huan-Qing Xie ◽  
Ya-Hao Wang ◽  
Lan Yu ◽  
Fang-Yuan Wang ◽  
...  
Keyword(s):  
Methyl Orange ◽  
Active Sites ◽  
High Performance ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Flower Structure ◽  
Electron Microscopies ◽  
Bet Method ◽  
One Step ◽  
Catalytic Active Sites

The removal of organic pollutants using green environmental photocatalytic degradation techniques urgently need high-performance catalysts. In this work, a facile one-step hydrothermal technique has been successfully applied to synthesize a Nb2O5 photocatalyst with uniform micro-flower structure for the degradation of methyl orange (MO) under UV irradiation. These nanocatalysts are characterized by transmission and scanning electron microscopies (TEM and SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) method, and UV-Vis diffuse reflectance spectroscopy (DRS). It is found that the prepared Nb2O5 micro-flowers presents a good crystal phases and consist of 3D hierarchical nanosheets with 400–500 nm in diameter. The surface area is as large as 48.6 m2 g−1. Importantly, the Nb2O5 micro-flowers exhibit superior catalytic activity up to 99.9% for the photodegradation of MO within 20 mins, which is about 60-fold and 4-fold larger than that of without catalysts (W/O) and commercial TiO2 (P25) sample, respectively. This excellent performance may be attributed to 3D porous structure with abundant catalytic active sites.

scholarly journals Isocratic High-Performance Liquid Chromatographic Method with Ultraviolet Detection for Simultaneous Determination of Levels of Voriconazole and Itraconazole and Its Hydroxy Metabolite in Human Serum

2005 ◽  
Vol 49 (8) ◽  
pp. 3569-3571 ◽  
Author(s):  
GholamAli Khoschsorur ◽  
Franz Fruehwirth ◽  
Sieglinde Zelzer
Keyword(s):  
Human Serum ◽  
Simultaneous Determination ◽  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Specific Method ◽  
Minimum Detectable Concentration ◽  
Detectable Concentration ◽  
One Step ◽  
Liquid Chromatographic

ABSTRACT A simple, specific method is presented for simultaneous determination of voriconazole and itraconazole and its metabolite, hydroxyitraconazole, in human serum using one-step liquid-liquid extraction and high-performance liquid chromatography. Linearity tests ranged from 0.1 to 8.0 μg/ml; the minimum detectable concentration was 0.03 μg/ml.

Improved rapid assay of uric acid in serum by liquid chromatography.

1988 ◽  
Vol 34 (12) ◽  
pp. 2567-2568 ◽  
Author(s):  
M Tanaka ◽  
M Hama
Keyword(s):  
Uric Acid ◽  
High Performance ◽  
Rapid Determination ◽  
Correlation Coefficients ◽  
Gel Permeation Chromatography ◽  
Serum Samples ◽  
Step Procedure ◽  
One Step ◽  
Highly Porous

Abstract This improved method for rapid determination of uric acid in serum is based on high-performance liquid-gel-permeation chromatography, with hydrophilic and highly porous vinyl alcohol copolymer as packing material. It has the following advantages: no need for sample deproteinization or use of a precolumn, more than 500 serum samples can be analyzed without having to regenerate or recondition the analytical apparatus, and the analysis for uric acid is a one-step procedure. Correlation coefficients between this method and other methods are very good (r = 0.998, 0.999).

Rational design of a highly mesoporous Fe–N–C/Fe3C/C–S–C nanohybrid with dense active sites for superb electrocatalysis of oxygen reduction

2020 ◽  
Vol 8 (44) ◽  
pp. 23436-23454
Author(s):  
Ahmed Al-Shahat Eissa ◽  
Nam Hoon Kim ◽  
Joong Hee Lee
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Active Sites ◽  
High Performance ◽  
Rational Design ◽  
Reduction Reaction ◽  
Single Step

A high-performance and sustainable electrocatalyst for the oxygen reduction reaction is fabricated by a single-step doping/annealing strategy.

Simple one-step preconcentration and cleanup with a micellar system for high performance liquid chromatography determination of pyrethroids in traditional Chinese medicine

2015 ◽  
Vol 7 (5) ◽  
pp. 1691-1700 ◽  
Author(s):  
Ligang Chen ◽  
Wenjuan Xing
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
High Performance ◽  
Micellar System ◽  
One Step

One-step preconcentration and cleanup using a micellar system for the extraction and preconcentration of four pyrethroids including beta-cyfluthrin, cyhalothrin, cyphenothrin and permethrin in traditional Chinese medicine with the use of Triton™ X-114.

scholarly journals Requirements for Beneficial Electrochemical Restructuring: A Model Study on a Cobalt Oxide in Selected Electrolytes

2021 ◽  
Author(s):  
Javier Villalobos ◽  
Diego Gonzales-Flores ◽  
Roberto Urcuyo ◽  
Mavis L. Montero ◽  
Götz Schuck ◽  
...  
Keyword(s):  
Active Sites ◽  
High Performance ◽  
Rational Design ◽  
Local Order ◽  
Current Increase ◽  
Model Study ◽  
Redox Active ◽  
Open Question ◽  
Diffraction Microscopy

<p>The requirements for beneficial materials restructuring into a higher performance OER electrocatalyst are still a largely open question. Here we use Erythrite (Co<sub>3</sub>(AsO<sub>4</sub>)<sub>2 </sub>8H<sub>2</sub>O) as a Co-based OER electrocatalyst to evaluate its catalytic properties during in-situ restructuring into an amorphous Co-based catalyst in four different electrolytes at pH 7. Using diffraction, microscopy and spectroscopy, we observed a strong effect in the restructuring kinetics depending of the anions in the electrolyte. Only carbonate electrolyte could activate the catalyst electrode, which we relate to its slow restructuring kinetics. While its turnover frequency (TOF) reduced from 2.84 O<sub>2 </sub>Co<sup>-1 </sup>s<sup>-1</sup> to a constant value of 0.10 O<sub>2</sub> Co<sup>-1 </sup>s<sup>-1</sup> after ~ 300 cycles, the number of redox active sites continuously increased, which explained the current increase of around 100%. The final activated material owns an adequate local order, a high Co oxidation state and a high number of redox-active Co ions, which we identify as the trinity for enhancing the OER activity. Thus, this work provides new insights into for the rational design of high-performance OER catalysts by electrochemical restructuring.</p>

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