scholarly journals Study of Ni(0)/La2O3 perovskite coated on monolith substrates as a promising catalyst for CO2 dry reforming with steam reforming of methane in syn-gas production

2021 ◽  
Vol 10 (1) ◽  
pp. 109-115
Author(s):  
Tri Tran Van ◽  
Phuong Ngo Thuy ◽  
Quan Ha Luu Manh ◽  
Thuy Luong Ngoc ◽  
Tuan Phan Trung ◽  
...  
Keyword(s):  
Active Sites ◽  
Hydrogen Reduction ◽  
Active Phase ◽  
Dip Coating ◽  
Gas Production ◽  
Co2 Reforming ◽  
Good Thermal Stability ◽  
Structured Catalysts ◽  
Structured Reactor ◽  
Coating Method

Coated monolith/foam catalysts are promising materials for chemistry applications due to structured reactor configuratiions providing low expansion coefficient, good thermal stability and low pressure loss. In this study, powedered Ni(0)/La2O3 catalysts in perovskite structures, were deposited on cordierite monolith substrates (2MgO-2Al2O3-5SiO2) by dip-coating method. The catalysts were characterized by N2 adsorption, XRD, TPR-H2 analysis. The activity of structured catalysts with various powder loadings (4, 8, 12, 20 and 30 wt %) were evaluated in combined Steam-CO2 reforming reaction (CH4/CO2/H2O = 2/1/2 vol%) at  GHSV = 60.000 h-1. XRD and TPR results showed that the active phase LaNiO3 were mainly Ni and La2O3distributed on the surface of cordierite channels after air calcination of 850oC, 3 hours and  hydrogen reduction of 600oC, 2 hours . The conversion of methane and CO2 on monolith catalysts, with proper active sites loadings of 12 – 20 wt%, were close to 80 vol% at 800oC. At the same reaction amount of active sites, the feedstock conversion on LaNiO3/monolith (12 %wt LaNiO3/monolith) was significantly higher than on corresponding powdered type, respectively 1.6 times of CH4, 1.8 times of CO2 conversion.

Electrochemical and Optical Properties of WO3 Prepared by Sol-Gel Coating

2007 ◽  
Vol 544-545 ◽  
pp. 1081-1084 ◽  
Author(s):  
Chang Yeoul Kim ◽  
Seong Geun Cho ◽  
Seok Park ◽  
Tae Yeoung Lim ◽  
Duck Kyun Choi
Keyword(s):  
Thin Film ◽  
Tungsten Oxide ◽  
Active Sites ◽  
Sol Gel ◽  
Dip Coating ◽  
Treatment Temperature ◽  
Starting Solution ◽  
Coating Method ◽  
Dip Coating Method ◽  
Xrd Patterns

Electrochromic WO3 thin film was prepared by using tungsten metal solution in hydrogen peroxide as a starting solution and by a sol-gel dip coating method. The thermal analysis was conducted by DSC/TG method. A DSC/TG analysis and the XRD patterns showed that a tungsten oxide crystal phase was formed at 400oC. WO3 thin film when heat-treated at 300oC was amorphous and had a better electrochemical property than that of the crystalline phase. Crystallization of tungsten oxide decreased active sites of ion intercalation so that the current density decreased with heat-treatment temperature.

Improving of Tribological Properties of Nanocomposites Sol-Gel Thin Films by Fluorocyclophosphazene Derivatives

2005 ◽  
Author(s):  
G. Celichowski ◽  
K. Chrobak
Keyword(s):  
Thin Films ◽  
Tribological Properties ◽  
Sol Gel ◽  
Dip Coating ◽  
Rf Plasma ◽  
Good Thermal Stability ◽  
Force Microscopy ◽  
Coating Method ◽  
Dip Coating Method ◽  
Sol Gel Films

Fluorocyclophospazenes’ derivatives were used as modifiers for improving tribological properties of thin films prepared by sol-gel technique. Thin films were made on the base of aminopropyltriethoxysilane (APTS). All films were deposited by dip-coating method and post-treated by heat, UV radiation and low pressure of RF plasma. Chemical changes in sol-gel films during all steps of post-treatments and modifications were monitored by FT-IR spectroscopy and SIMS spectrometry. Topographies of modified surfaces were imaged by Atomic Force Microscopy (AFM). After final modification significant improvements of frictional properties were observed as well as their very good thermal stability.

What catalysis needs from the electron microscopist

1988 ◽  
Vol 46 ◽  
pp. 694-695
Author(s):  
Alexis T. Bell
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Catalyst Deactivation ◽  
Surface Composition ◽  
Internal Surface ◽  
Active Phase ◽  
Atomic Scale ◽  
Metal Catalyst ◽  
Internal Surface Area ◽  
Porous Support

Heterogeneous catalysts, used in industry for the production of fuels and chemicals, are microporous solids characterized by a high internal surface area. The catalyticly active sites may occur at the surface of the bulk solid or of small crystallites deposited on a porous support. An example of the former case would be a zeolite, and of the latter, a supported metal catalyst. Since the activity and selectivity of a catalyst are known to be a function of surface composition and structure, it is highly desirable to characterize catalyst surfaces with atomic scale resolution. Where the active phase is dispersed on a support, it is also important to know the dispersion of the deposited phase, as well as its structural and compositional uniformity, the latter characteristics being particularly important in the case of multicomponent catalysts. Knowledge of the pore size and shape is also important, since these can influence the transport of reactants and products through a catalyst and the dynamics of catalyst deactivation.

Porous Gel Coatings Obtained by Phase Separation in ORMOSIL System

2000 ◽  
Vol 628 ◽  
Author(s):  
Kazuki Nakanishi ◽  
Souichi Kumon ◽  
Kazuyuki Hirao ◽  
Hiroshi Jinnai
Keyword(s):  
Phase Separation ◽  
Reaction Time ◽  
Volume Fraction ◽  
Sol Gel ◽  
Reaction Times ◽  
Dip Coating ◽  
Coating Solution ◽  
Coating Method ◽  
Gel Phase ◽  
Dip Coating Method

ABSTRACTMacroporous silicate thick films were prepared by a sol-gel dip-coating method accompanied by the phase separation using methyl-trimethoxysilane (MTMS), nitric acid and dimethylformamide (DMF) as starting components. The morphology of the film varied to a large extent depending on the time elapsed after the hydrolysis until the dipping of the coating solution. On a glass substrate, the films prepared by early dipping had inhomogeneous submicrometer-sized pores on the surface of the film. At increased reaction times, relatively narrow sized isolated macropores were observed and their size gradually decreased with the increase of reaction time. On a polyester substrate, in contrast, micrometer-sized isolated spherical gel domains were homogeneously deposited by earlier dippings. With an increase of reaction time, the volume fraction of the gel phase increased, then the morphology of the coating transformed into co-continuous gel domains and macropores, and finally inverted into the continuous gel domains with isolated macropores. The overall morphological variation with the reaction time was explained in terms of the phase separation and the structure freezing by the forced gelation, both of which were induced by the evaporation of methanol during the dipping operation.

PREPARATION AND CHARACTERIZATION OF POLYVINYL ALCOHOL THIN FILMS FOR ORGANIC THIN FILM TRANSISTORS AND BIOMEDICAL APPLICATIONS

2018 ◽  
Vol 5 (2) ◽  
pp. 16-18
Author(s):  
Chandar Shekar B ◽  
Ranjit Kumar R ◽  
Dinesh K.P.B ◽  
Sulana Sundar C ◽  
Sunnitha S ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thin Film Transistors ◽  
Gravimetric Method ◽  
Dip Coating ◽  
Organic Thin Film Transistors ◽  
Poly Vinyl Alcohol ◽  
Organic Thin Film ◽  
Glass Substrates ◽  
Coating Method

Thin films of poly vinyl alcohol (PVA) were prepared on pre-cleaned glass substrates by Dip Coating Method. FTIR spectrum was used to identify the functional groups present in the prepared films. The vibrational peaks observed at 1260 cm-1 and 851 cm-1 are assigned to C–C stretching and CH rocking of PVA.The characteristic band appearing at 1432 cm-1 is assigned to C–H bend of CH2 of PVA. The thickness of the prepared thin films were measured by using an electronic thickness measuring instrument (Tesatronic-TTD20) and cross checked by gravimetric method. XRD spectra indicated the amorphous nature of the films.Surface morphology of the coated films was studied by scanning electron microscope (SEM). The surface revealed no pits and pin holes on the surface. The observed surface morphology indicated that these films could be used as dielectric layer in organic thin film transistors and as drug delivery system for wound healing.

scholarly journals Preparation of Polypropylene/PVDF Composite Membrane by Dip-Coating Method

2021 ◽  
Vol 1115 (1) ◽  
pp. 012028
Author(s):  
P T P Aryanti ◽  
G Trilaksono ◽  
A Hotmaida ◽  
M A Afifah ◽  
F P Pratiwi ◽  
...  
Keyword(s):  
Composite Membrane ◽  
Dip Coating ◽  
Coating Method ◽  
Dip Coating Method

scholarly journals Heat Scanning for the Fabrication of Conductive Fibers

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1405
Author(s):  
Jina Jang ◽  
Haoyu Zhou ◽  
Jungbae Lee ◽  
Hakgae Kim ◽  
Jung Bin In
Keyword(s):  
Silver Nanowires ◽  
Building Blocks ◽  
Dip Coating ◽  
Coating Materials ◽  
Scanning Time ◽  
Silver Ink ◽  
Nylon Fiber ◽  
Coating Method ◽  
Conductive Fibers ◽  
Tubular Heater

Conductive fibers are essential building blocks for implementing various functionalities in a textile platform that is highly conformable to mechanical deformation. In this study, two major techniques were developed to fabricate silver-deposited conductive fibers. First, a droplet-coating method was adopted to coat a nylon fiber with silver nanoparticles (AgNPs) and silver nanowires (AgNWs). While conventional dip coating uses a large ink pool and thus wastes coating materials, droplet-coating uses minimal quantities of silver ink by translating a small ink droplet along the nylon fiber. Secondly, the silver-deposited fiber was annealed by similarly translating a tubular heater along the fiber to induce sintering of the AgNPs and AgNWs. This heat-scanning motion avoids excessive heating and subsequent thermal damage to the nylon fiber. The effects of heat-scanning time and heater power on the fiber conductance were systematically investigated. A conductive fiber with a resistance as low as ~2.8 Ω/cm (0.25 Ω/sq) can be produced. Finally, it was demonstrated that the conductive fibers can be applied in force sensors and flexible interconnectors.

Characterization of UHMWPE- HAp coating produced by dip coating method on Ti6Al4V alloy

2021 ◽  
pp. 127091
Author(s):  
Gözde Çelebi Efe ◽  
Elif Yenilmez ◽  
İbrahim Altinsoy ◽  
Serbülent Türk ◽  
Cuma Bindal
Keyword(s):  
Dip Coating ◽  
Ti6al4v Alloy ◽  
Coating Method ◽  
Dip Coating Method

scholarly journals Synergistic Effect of Alkali Na and K Promoter on Fe-Co-Cu-Al Catalysts for CO2 Hydrogenation to Light Hydrocarbons

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 735
Author(s):  
Yuhao Zheng ◽  
Chenghua Xu ◽  
Xia Zhang ◽  
Qiong Wu ◽  
Jie Liu
Keyword(s):  
Synergistic Effect ◽  
Active Sites ◽  
Intermediate Formation ◽  
Active Phase ◽  
Dissociative Adsorption ◽  
Co2 Hydrogenation ◽  
Chain Growth ◽  
Co2 Conversion ◽  
Light Hydrocarbons ◽  
Active Centers

Alkali metal K- and/or Na-promoted FeCoCuAl catalysts were synthesized by precipitation and impregnation, and their physicochemical and catalytic performance for CO2 hydrogenation to light hydrocarbons was also investigated in the present work. The results indicate that Na and/or K introduction leads to the formation of active phase metallic Fe and Fe-Co crystals in the order Na < K < K-Na. The simultaneous introduction of Na and K causes a synergistic effect on increasing the basicity and electron-rich property, promoting the formation of active sites Fe@Cu and Fe-Co@Cu with Cu0 as a crystal core. These effects are advantageous to H2 dissociative adsorption and CO2 activation, giving a high CO2 conversion with hydrogenation. Moreover, electron-rich Fe@Cu (110) and Fe-Co@Cu (200) provide active centers for further H2 dissociative adsorption and O-C-Fe intermediate formation after adsorption of CO produced by RWGS. It is beneficial for carbon chain growth in C2+ hydrocarbons, including olefins and alkanes. FeCoCuAl simultaneously modified by K-Na exhibits the highest CO2 conversion and C2+ selectivity of 52.87 mol% and 89.70 mol%, respectively.

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