The role of oxygen vacancies in biomass deoxygenation by reducible zinc/zinc oxide catalysts

2018 ◽  
Vol 8 (7) ◽  
pp. 1819-1827 ◽  
Author(s):  
Xiao Xiao ◽  
Helen Bergstrom ◽  
Ryan Saenger ◽  
Benjamin Johnson ◽  
Runcang Sun ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Metal Oxides ◽  
Oxygen Vacancies ◽  
Oxide Catalysts ◽  
Selective Removal

Selective removal of oxygen is the key challenge in the upgrading of biomass-derived molecules, and reducible metal oxides have shown the ability to catalytically remove oxygen even at low exogenous H2 pressures.

ZINC OXIDE VERSUS MAGNESIUM OXIDE REVISITED. PART 1

2012 ◽  
Vol 85 (1) ◽  
pp. 38-55 ◽  
Author(s):  
Manuel Guzmán ◽  
Berta Vega ◽  
Núria Agulló ◽  
Ulrich Giese ◽  
Salvador Borrós
Keyword(s):  
Zinc Oxide ◽  
Environmental Impact ◽  
Natural Rubber ◽  
Metal Oxides ◽  
Environmental Effects ◽  
Model Compound ◽  
Rubber Industry ◽  
Sulfur Vulcanization ◽  
Activator System

Abstract Zinc oxide is a widely used compound in the rubber industry due to the excellent properties that it shows as activator, and consequently, its role in the mechanism of accelerated sulfur vulcanization has been extensively studied. Due to the increased concern about its environmental effects, several research studies have been carried out in order to substitute it with different metal oxides such us MgO. The effect of the activator system in order to minimize the environmental impact of the rubber goods has been explored. The work developed is presented in two parts. In Part 1, the influence of different mixtures of ZnO and MgO on the vulcanization of natural rubber has been investigated. In Part 2, model compound vulcanization has been used to study the role of MgO on the mechanism to gain a better understanding of the differences shown in Part 1.

Determining the role of oxygen vacancies in palmitone selectivity and coke formation over acid metal oxide catalysts for the ketonization of methyl palmitate

2021 ◽  
pp. 118405
Author(s):  
Adisak Guntida ◽  
Thanwarat Rattanachartnarong ◽  
Bunjerd Jongsomjit ◽  
Tawan Sooknoi ◽  
Patcharaporn Weerachawanasak ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Methyl Palmitate ◽  
Oxygen Vacancies ◽  
Coke Formation ◽  
Oxide Catalysts ◽  
Metal Oxide Catalysts

ZINC OXIDE VERSUS MAGNESIUM OXIDE REVISITED. PART 2

2012 ◽  
Vol 85 (1) ◽  
pp. 56-67 ◽  
Author(s):  
Manuel Guzmán ◽  
Berta Vega ◽  
Núria Agulló ◽  
Salvador Borrós
Keyword(s):  
Zinc Oxide ◽  
Environmental Impact ◽  
Natural Rubber ◽  
Metal Oxides ◽  
Environmental Effects ◽  
Model Compound ◽  
Rubber Industry ◽  
Sulfur Vulcanization ◽  
Activator System

Abstract Zinc oxide is a widely used compound in the rubber industry due to the excellent properties that it shows as an activator and, consequently, its role in the mechanism of accelerated sulfur vulcanization has been extensively studied. Due to the increased concern about its environmental effects, several research studies have been carried out in order to substitute it with different metal oxides such us MgO. The effect of the activator system in order to minimize the environmental impact of the rubber goods has been explored. The work developed is presented in two parts. In Part 1, the influence of different mixtures of ZnO and MgO in the vulcanization of natural rubber has been investigated. In Part 2 of the study, model compound vulcanization has been used to study the role of MgO on the mechanism to gain a better understanding of the differences shown in the first part.

Regulating activation pathway of Cu/persulfate through the incorporation of unreducible metal oxides: Pivotal role of surface oxygen vacancies

2021 ◽  
Vol 286 ◽  
pp. 119914
Author(s):  
Xinquan Zhou ◽  
Ali Jawad ◽  
Mengyi Luo ◽  
Chunguang Luo ◽  
Tingting Zhang ◽  
...  
Keyword(s):  
Metal Oxides ◽  
Oxygen Vacancies ◽  
Pivotal Role ◽  
Surface Oxygen ◽  
Activation Pathway

Short Review: Role of Metal Oxides as Filler in Polysiloxane Sheet Composite

2013 ◽  
Vol 465-466 ◽  
pp. 27-31 ◽  
Author(s):  
Sufiah Mohamad Yahya ◽  
A. Azmi ◽  
Maizlinda Izwana Idris ◽  
Muhamad Zaini Yunos ◽  
Shahruddin Mahzan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Zinc Oxide ◽  
Metal Oxides ◽  
Injection Moulding ◽  
Zirconium Carbide ◽  
Physical And Mechanical Properties ◽  
Short Review ◽  
Fabrication Technique

Additional of fillers such as silica (SiO2), alumina (Al2O3), zinc oxide (ZnO), Zirconium carbide ( ZrC) and Zirconia (ZrO2) would affect the properties of the polysiloxane sheet, that can be applied in various applications. Polysiloxane sheet composites are largely use today with various materials as fillers. The fabrication techniques of the polysiloxane composite sheets include micro-moulding, casting moulding and injection moulding. Application of different fabricating process, physical and mechanical properties of polysiloxane sheet composites. Thus, this paper complies various studies with regards to the various properties of polysiloxane sheet composites established by incorporation of different fabrication technique and fillers.

The Role of Metal Oxides as Activators of Vulcanization

1958 ◽  
Vol 31 (3) ◽  
pp. 526-538 ◽  
Author(s):  
M. Feldstein ◽  
P. Orlovsky ◽  
B. Dogadkin
Keyword(s):  
Zinc Oxide ◽  
Metal Oxides ◽  
Calcium Hydroxide ◽  
Large Degree ◽  
Positive Influence ◽  
Butadiene Rubber ◽  
Activation Effect ◽  
Vulcanization Process ◽  
Butadiene Styrene

Abstract 1. The activation effect of metal oxides on the process of culvanization of nonpigmented compounds of rod polymerized sodium butadiene rubber differs from the effect in rodless polymerized rubber. In the latter case zinc oxide not only is not an activator but it retards the vulcanization process. 2. The role of activators depends, to a large degree, on the type of vulcanization accelerator and active filler used. 3. Metal oxides increase the amount of structure formation in the vulcanizate. 4. With regard to butadiene styrene rubber (SKS-30A), calcium hydroxide appears to have stronger activating effect on vulcanization than zinc oxide. 5. The special effectiveness of calcium hydroxide in compounds of butadiene styrene rubber is a result of its independent structure forming ability and accelerating influence on the reaction between rubber and sulfur. 6. Magnesium oxide has a positive influence on the technical properties of rubber and on the durability of tires prepared with butadiene styrene and sodium butadiene rubbers.

scholarly journals A critical review of synthesis parameters affecting the properties of zinc oxide nanoparticle and its application in wastewater treatment

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
E. Y. Shaba ◽  
J. O. Jacob ◽  
J. O. Tijani ◽  
M. A. T. Suleiman
Keyword(s):  
Zinc Oxide ◽  
Metal Oxides ◽  
Zinc Oxide Nanoparticles ◽  
Textural Properties ◽  
Oxide Nanoparticles ◽  
Zinc Oxide Nanoparticle ◽  
Synthesis Parameters ◽  
Metal Precursors ◽  
Removal Of Heavy Metals ◽  
Oxide Nanoparticle

AbstractIn this era, nanotechnology is gaining enormous popularity due to its ability to reduce metals, metalloids and metal oxides into their nanosize, which essentially alter their physical, chemical, and optical properties. Zinc oxide nanoparticle is one of the most important semiconductor metal oxides with diverse applications in the field of material science. However, several factors, such as pH of the reaction mixture, calcination temperature, reaction time, stirring speed, nature of capping agents, and concentration of metal precursors, greatly affect the properties of the zinc oxide nanoparticles and their applications. This review focuses on the influence of the synthesis parameters on the morphology, mineralogical phase, textural properties, microstructures, and size of the zinc oxide nanoparticles. In addition, the review also examined the application of zinc oxides as nanoadsorbent for the removal of heavy metals from wastewater.

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