scholarly journals Cerium promoted V-g-C 3 N 4 as highly efficient heterogeneous catalysts for the direct benzene hydroxylation

2018 ◽  
Vol 5 (6) ◽  
pp. 180371 ◽  
Author(s):  
Cheng Wang ◽  
Liya Hu ◽  
Meiyin Wang ◽  
Bin Yue ◽  
Heyong He
Keyword(s):  
Heterogeneous Catalysts ◽  
High Dispersion ◽  
Adsorption Ability ◽  
Cerium Content ◽  
Assembly Method ◽  
Benzene Hydroxylation ◽  
Hydroxylation Reaction ◽  
Catalytic Stability ◽  
Vanadium Species ◽  
Active Centres

A series of Ce x -V-g-C 3 N 4 catalysts with different cerium content were synthesized by a facile co-assembly method. Compared with pure V-g-C 3 N 4 catalyst, the addition of cerium facilitated the high dispersion of vanadium species as well as the benzene adsorption ability of the corresponding catalysts. Also, the existence of cerium promoted the partial reduction of vanadium species, which improved the redox property of vanadium species as the active centres. The Ce x -V-g-C 3 N 4 catalysts showed considerably improved activity in the benzene hydroxylation reaction compared with V-g-C 3 N 4 catalyst. Among the catalysts studied, Ce 0.07 -0.07 V-g-C 3 N 4 exhibited the best catalytic activity with a benzene conversion of 33.7% and a phenol yield of 32.3% with good structural and catalytic stability, while only 24.7% of benzene conversion and phenol yield of 24.2% were obtained over 0.07 V-g-C 3 N 4 .

Photocatalytic hydroxylation of benzene to phenol over organosilane-functionalized FeVO4 nanorods

2021 ◽  
Author(s):  
Danlei Wei ◽  
Lianqi Huang ◽  
Hanying Liang ◽  
Junhua Zou ◽  
Wenwen Chen ◽  
...  
Keyword(s):  
Synthetic Approach ◽  
Hydroxylation Of Benzene ◽  
Phenol Synthesis ◽  
Benzene Hydroxylation ◽  
Hydroxylation Reaction

Photocatalytic benzene hydroxylation reaction using clean oxidant such as H2O2 is a green synthetic approach for phenol synthesis. Here, our study shows that the silylated iron vanadate (FeVO4) nanorods can...

Nature of vanadium species on vanadium silicalite-1 zeolite and their stability in hydroxylation reaction of benzene to phenol

2011 ◽  
Vol 1 (6) ◽  
pp. 1060 ◽  
Author(s):  
Bin Guo ◽  
Liangfang Zhu ◽  
Xiaoke Hu ◽  
Qian Zhang ◽  
Dongmei Tong ◽  
...  
Keyword(s):  
Hydroxylation Reaction ◽  
Vanadium Species

The concept, reality and utility of single-site heterogeneous catalysts (SSHCs)

2014 ◽  
Vol 16 (17) ◽  
pp. 7647-7661 ◽  
Author(s):  
John Meurig Thomas
Keyword(s):  
Heterogeneous Catalysts ◽  
Metal Organic Framework ◽  
Single Site ◽  
Inner Surface ◽  
Metal Organic ◽  
Active Centres ◽  
Organic Framework

The large-pores of this metal–organic framework allow bulky reactants to be catalytically converted at single-site active centres situated at the inner surface.

Effect of Ultrasound on the Properties of Heterogeneous Catalysts for Sono-Fenton Oxidation Processes

2008 ◽  
Vol 11 (1) ◽  
Author(s):  
Juan A. Melero ◽  
Fernando Martínez ◽  
Raúl Molina
Keyword(s):  
Particle Size ◽  
Iron Oxides ◽  
Heterogeneous Catalysts ◽  
Reaction Medium ◽  
Catalyst Particle ◽  
Ultrasound Irradiation ◽  
Catalytic Performance ◽  
Nanocomposite Material ◽  
High Dispersion ◽  
Concentration Changes

AbstractThe objective of this research is to assess the effect of ultrasonic irradiation (20 KHz) on the catalytic activity and catalyst particle size of different iron-containing solids (hematite/SBA-15 nanocomposite; hematite; goethite). The catalytic activities of the different catalysts were investigated in the sono-Fenton degradation of a phenolic aqueous solution in the presence of hydrogen peroxide at pH 3. The catalytic performance was monitored in terms of phenol and total organic carbon (TOC) conversions. The concentration changes of different by-products coming from incomplete mineralization of phenol were also monitored. The stability was examined by measuring iron dissolved in the reaction medium after reaction. The degradation rate in the presence of the nanocomposite material was higher than that when SBA-15 and hematite were separately suspended and also higher than that found for the bulk and unsupported iron oxides (hematite and goethite). The particle size of the catalysts suffers serious changes during the sonication which strongly depend on their nature. Unlike nanocomposite material which presents a deep catalyst particle reduction, unsupported bulk iron oxides yield an agglomeration of the particles. The considerable enhancement of the activity achieved with the nanocomposite material is due to the catalyst particles size reduction during ultrasound irradiation as well as the high dispersion of the metallic species over the mesostructured support.

scholarly journals Cold Plasma Preparation of Pd/Graphene Catalyst for Reduction of p-Nitrophenol

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1341
Author(s):  
Qian Zhao ◽  
Decai Bu ◽  
Zhihui Li ◽  
Xiuling Zhang ◽  
Lanbo Di
Keyword(s):  
Metal Nanoparticles ◽  
Cold Plasma ◽  
Heterogeneous Catalysts ◽  
Catalytic Reduction ◽  
Pd Nanoparticles ◽  
Atomic Ratio ◽  
Thermal Reduction ◽  
High Dispersion ◽  
Pd Catalysts ◽  
Metal Support Interaction

Supported metal nanoparticles with small size and high dispersion can improve the performance of heterogeneous catalysts. To prepare graphene-supported Pd catalysts, graphene and PdCl2 were used as support and Pd precursors, respectively. Pd/G-P and Pd/G-H catalysts were prepared by cold plasma and conventional thermal reduction, respectively, for the catalytic reduction of p-nitrophenol (4-NP). The reaction followed quasi-first-order kinetics, and the apparent rate constant of Pd/G-P and Pd/G-H was 0.0111 and 0.0042 s−1, respectively. The graphene support was exfoliated by thermal reduction and cold plasma, which benefits the 4-NP adsorption. Pd/G-P presented a higher performance because cold plasma promoted the migration of Pd species to the support outer surface. The Pd/C atomic ratio for Pd/G-P and Pd/G-H was 0.014 and 0.010, respectively. In addition, the Pd nanoparticles in Pd/G-P were smaller than those in Pd/G-H, which was beneficial for the catalytic reduction. The Pd/G-P sample presented abundant oxygen-containing functional groups, which anchored the metal nanoparticles and enhanced the metal-support interaction. This was further confirmed by the shift in the binding energy to a high value for Pd3d in Pd/G-P. The cold plasma method operated under atmospheric pressure is effective for the preparation of Pd/G catalysts with enhanced catalytic activity for 4-NP reduction.

scholarly journals PREPARATION, CHARACTERIZATION AND CATALYTIC ACTIVITY OF CuO/TS-1 ON BENZENE HYDROXYLATION REACTION

2012 ◽  
Vol 15 (2) ◽  
Author(s):  
Nuni Widiarti ◽  
Ratna Ediati ◽  
Hamzah Fansuri ◽  
Didik Prasetyoko
Keyword(s):  
Catalytic Activity ◽  
Benzene Hydroxylation ◽  
Hydroxylation Reaction

scholarly journals Highly Active Fenton-Like Catalyst Derived from Solid Waste-Iron Ore Tailings Using Wheat Straw Pyrolysis

2021 ◽  
Author(s):  
Lihui Gao ◽  
Lizhang Wang ◽  
Shulei Li ◽  
Yijun Cao
Keyword(s):  
Wheat Straw ◽  
Active Sites ◽  
Iron Ore ◽  
Heterogeneous Catalysts ◽  
Redox Cycles ◽  
Highly Active ◽  
Iron Ore Tailings ◽  
Catalytic Stability ◽  
Iron Active Sites

Abstract The pollutants degradation rate of iron ore tailings-based heterogeneous catalysts is the main factor limiting its application. Herein, an iron ore tailings-based Fenton-like catalyst(I/W(3:1)-900-60) with relative fast catalysis rate was constructed by co-pyrolysis(900 ℃, 60min holding time) of iron ore tailings and wheat straw with mass ratio of 3:1. With wheat straw blending, the generated I/W(3:1)-900-60 presented a larger surface area(24.3 m2/g), smaller pore size(3.707 nm), reduced iron species (Fe2+ from magnetic) and a higher catalytic activity(0.0229 min-1) than I-900-60 (1.196 m2/g, 12.935 nm, 0.012 min-1) pyrolyzed using a single iron ore tailings under the same pyrolysis conditions. In addition, biochar and iron ore tailings in I/W(3:1)-900-60 were tightly combined through chemical bonding. The optimal catalyst remains active after three cycles, indicating its catalytic stability and recyclability. The good Fenton-like MB degradation efficiency of I/W(3:1)-900-60 was ascribed to the sacrificial role of biochar, as well as the electron transfer between biochar and iron active sites or the redox cycles of ≡Fe3+/Fe2+. This finding provides a facile construction strategy for a highly active iron ore tailings-based Fenton-like catalyst, and thereby had a great potential application in wastewater treatment.

scholarly journals Intercalating Lithium into Lattice of Silver Nanoparticles boosts Catalytic Hydrogenation of Carbon-Oxygen Bond

2021 ◽  
Author(s):  
Xinping Duan ◽  
Youzhu Yuan ◽  
Benedict Tsz Woon Lo ◽  
Lin Ye ◽  
Lele Huang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Silver Nanoparticles ◽  
Melting Point ◽  
Catalytic Hydrogenation ◽  
Heterogeneous Catalysts ◽  
Major Obstacle ◽  
High Dispersion ◽  
Highly Efficient ◽  
Coinage Metals ◽  
Oxygen Bond

Coinage metals nanoparticles with high dispersion can serve as highly efficient heterogeneous catalysts. However, owing to their low melting point, poor thermal stability remains a major obstacle towards applications under...

scholarly journals High-entropy intermetallics serve an ultrastable single-atom Pt for propane dehydrogenation

2021 ◽  
Author(s):  
Yuki Nakaya ◽  
Eigo Hayashida ◽  
Hiroyuki Asakura ◽  
Ken-ichi Shimizu ◽  
Shinya Furukawa
Keyword(s):  
Heterogeneous Catalysts ◽  
Coke Formation ◽  
Propane Dehydrogenation ◽  
Single Atom ◽  
Side Reactions ◽  
High Entropy ◽  
New Class ◽  
Catalyst Life ◽  
Catalytic Stability ◽  
Propylene Production

Propane dehydrogenation (PDH) has been a promising propylene production process that can compensate for the increasing global demand for propylene. However, Pt-based catalysts with high stability at ≥600°C have barely been reported because the catalysts typically result in short catalyst life owing to side reactions and coke formation. Herein, we report a new class of heterogeneous catalysts using high-entropy intermetallics (HEIs). Pt–Pt ensembles, which cause side reactions, are entirely diluted by the component inert metals in PtGe-type HEI; thereby, unfavorable side reactions are drastically inhibited. The resultant HEI: (PtCoCu)(GeGeSn)/Ca–SiO2 exhibited an outstandingly high catalytic stability, even at 600°C (kd−1 = τ = 4146 h = 173 d), and almost no deactivation of the catalyst was observed two months for the first time.

Sign in / Sign up

Export Citation Format

Share Document