Enhanced release of palladium and platinum from catalytic converter materials exposed to ammonia and chloride bearing solutions

2019 ◽  
Vol 21 (1) ◽  
pp. 133-144 ◽  
Author(s):  
Deborah M. Aruguete ◽  
Mitsuhiro Murayama ◽  
Terry Blakney ◽  
Christopher Winkler
Keyword(s):  
Electron Microscopy ◽  
Catalytic Converter ◽  
Elevated Salinity ◽  
Metallic Palladium ◽  
Palladium Platinum

Results suggest that systems with elevated salinity and trace ammonia could induce release of palladium/platinum from emitted vehicle catalytic converter (VCC) materials; electron microscopy suggests the presence of non-metallic palladium in VCCs.

High Resolution Transmission Electron Microscopy of an automobile catalytic converter

1990 ◽  
Vol 48 (4) ◽  
pp. 242-243
Author(s):  
Jan-Olle Malm ◽  
Jan-Olov Bovin
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Catalytic Converter ◽  
Active Material ◽  
Image Intensifier ◽  
High Resolution Electron Microscopy ◽  
Detailed Knowledge ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Atomic Surface

Understanding of catalytic processes requires detailed knowledge of the catalyst. As heterogeneous catalysis is a surface phenomena the understanding of the atomic surface structure of both the active material and the support material is of utmost importance. This work is a high resolution electron microscopy (HREM) study of different phases found in a used automobile catalytic converter.The high resolution micrographs were obtained with a JEM-4000EX working with a structural resolution better than 0.17 nm and equipped with a Gatan 622 TV-camera with an image intensifier. Some work (e.g. EDS-analysis and diffraction) was done with a JEM-2000FX equipped with a Link AN10000 EDX spectrometer. The catalytic converter in this study has been used under normal driving conditions for several years and has also been poisoned by using leaded fuel. To prepare the sample, parts of the monolith were crushed, dispersed in methanol and a drop of the dispersion was placed on the holey carbon grid.

scholarly journals Emission Control In Diesel Engine using Magnesium as a Catalyst

2019 ◽  
Vol 8 (2S5) ◽  
pp. 196-199
Keyword(s):  
Environmental Pollution ◽  
Pollution Control ◽  
Control Method ◽  
Catalytic Converter ◽  
Nano Particles ◽  
Motor Vehicles ◽  
Rapid Urbanization ◽  
Precautionary Measures ◽  
Two Wheeler ◽  
Palladium Platinum

Most cities in the world are subjected to rapid urbanization and a majority of the country’s population is estimated to move towards the cities within a span of the two decades. Majority of Population in all over country expects to live in a city, Such that most cities face rapid Urbanization. The fast growth in urban cities has stemmed in an incredible growth in the quantity of motor vehicles. In some major cities, the motor vehicles are doubled in the last decade. The numbers of vehicles used in cities have almost tripled its usage in a number of Automobiles by few decades. The majority of environmental pollution is caused by two-wheelers in large number. This results in a massive environmental pollution. A serious prerequisite for most effective precautionary measures has to be carried out. The emission controlled by dual techniques to control the pollution specifically, pre-pollution and post pollution control. Here the investigation is conceded out by establishing the post pollution control method for the two-wheeler automobiles via magnesium as a catalyst. To accomplish this objective, a pioneering proposal of catalytic converter is offered using magnesium as a catalyst for two-wheeler automobiles. The projected technique is precise operational in the deterrence of conservational pollution contributed from two-wheeler automobiles. It encompasses the consumption of magnesium which is economical than the, palladium, platinum and rhodium nano-particles used in automobiles.

scholarly journals Design and Fabrication of Three-Way Catalytic Converter by using Al2O3 and SiO2 Coating as aCatalyst and Access of Emission Characteristics in C.I. Engine

2019 ◽  
Vol 8 (12) ◽  
pp. 1136-1143
Keyword(s):  
Silicon Dioxide ◽  
Catalytic Converter ◽  
Aluminium Oxide ◽  
Maximum Load ◽  
Emission Rates ◽  
Toxic Gases ◽  
Hydrocarbon Emission ◽  
The Cost ◽  
Co Emission ◽  
Palladium Platinum

Catalytic converter is basically a device which is used to convert toxic harmful gases into less harmful gases from the exhaust of a automobile. Without this device, toxic gases which are emitted from the exhaust of an automobile can’t be converted to less toxic gases. An existing and catalytic converter which is present currently in the market uses catalyst of Platinum group such as Palladium, Platinum and Rhodium which are highly expensive catalyst. Therefore, to improve the durability and to reduce the cost of the catalytic converter, we are replacing the coating of catalyst by Aluminium Oxide and Silicon Dioxide which have high thermal stability, durability and are available are cheaper rates. This project focuses on the methodology involved in the fabrication of new catalytic converter and analysing the emission rates of toxic gases like Nitrogen Oxides, Carbon Monoxide and hydrocarbons. The Silicon Dioxide coated converter reduces the NOx and CO emission and the Aluminium Oxide coated converter reduces the CO and HC emission. The nitrogen oxide gases have been reduced 20.38% at maximum load and 55.2% at minimum load using Silicon dioxide coated convertor. The hydrocarbon emission has been reduced up to 88.8% at maximum load and 80% at minimum load. CO emissions were reduced by 75% and 80% at maximum and minimum loads in both the converters.

Scale Surface and Scale/Alloy Interface for Alumina-Forming Alloys with Noble Metal and Yttrium

2011 ◽  
Vol 696 ◽  
pp. 94-100
Author(s):  
Tadaaki Amano
Keyword(s):  
Electron Microscopy ◽  
Water Vapor ◽  
Noble Metal ◽  
Mass Gain ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Oxygen Oxygen ◽  
Oxide Adherence ◽  
Scale Surface ◽  
Palladium Platinum

Scale surface and scale/alloy interface for alumina-forming (Fe-20Cr-4Al) alloys with noble metal (palladium, platinum) and yttrium were studied in oxidizing atmospheres (oxygen, oxygen-water vapor) for 18ks at 1473, 1573 and 1673K, by mass gain measurements, amount of spalled oxide, X-ray diffraction (XRD), scanning electron microscopy (SEM) and field emission-transmission electron microscopy/energy dispersive spectroscopy (FE-TEM/EDS). After oxidation at 1473K for 18ks in oxygen, the mass gains of the FeCrAl, FeCrAlPd and FeCrAlPt alloys showed almost the same values. Those of the FeCrAlY alloys decreased with increasing yttrium of up to 0.1% followed by an increase with the yttrium content. The mass gain of the FeCrAlPtY alloys with appropriate additions of platinum and yttrium were lower than that of the FeCrAlY alloy with 0.1mass% yttrium, and alumina/alloy interface of the alloy showed good coherency by TEM. The scale surface of the FeCrAl, FeCrAlPd and FeCrAlPt alloys were rough, however, those of the FeCrAlY and FeCrAlPtY alloys were smooth. After oxidation at 1673K for 18ks in water-vapor (47vol%), FeCrAlPt alloy with 0.5mass% platinum showed good oxide adherence. Platinum concentration was observed at alloy side of the alumina/alloy interface by FE TEM/EDS.

Platinum Compounds as Stains for Electron Microscopy

1974 ◽  
Vol 32 ◽  
pp. 230-231
Author(s):  
S. K. Aggarwal ◽  
P. McAllister ◽  
R. W. Wagner ◽  
B. Rosenberg
Keyword(s):  
Electron Microscopy ◽  
Hela Cells ◽  
Uranyl Acetate ◽  
Sarcoma 180 ◽  
Platinum Compounds ◽  
Kb Cells ◽  
En Bloc ◽  
Human Lymphoma ◽  
Ultrathin Sections ◽  
Blue Coloration

Uranyl acetate has been used as an electron stain for en bloc staining as well as for staining ultrathin sections in conjunction with various lead stains (Fig. 1). Present studies reveal that various platinum compounds also show promise as electron stains. Certain platinum compounds have been shown to be effective anti-tumor agents. Of particular interest are the compounds with either uracil or thymine as one of the ligands (cis-Pt(II)-uracil; cis-Pt(II)-thymine). These compounds are amorphous, highly soluble in water and often exhibit an intense blue coloration. These compounds show enough electron density to be used as stains for electron microscopy. Most of the studies are based on various cell lines (human AV, cells, human lymphoma cells, KB cells, Sarcoma-180 ascites cells, chick fibroblasts and HeLa cells) while studies on tissue blocks are in progress.

Immune Electron Microscopy (IEM) of a Canine Adeno-Associated Virus

1974 ◽  
Vol 32 ◽  
pp. 256-257
Author(s):  
Gunter F. Thomas ◽  
M. David Hoggan
Keyword(s):  
Electron Microscopy ◽  
Cell Cultures ◽  
Complement Fixation ◽  
Hepatitis Virus ◽  
Wide Distribution ◽  
Immune Electron Microscopy ◽  
Adeno Associated Virus ◽  
Virus Like Particle ◽  
Dog Kidney ◽  
Green Monkeys

In 1968, Sugimura and Yanagawa described a small 25 nm virus like particle in association with the Matsuda strain of infectious canine hepatitis virus (ICHV). Domoto and Yanagawa showed that this particle was dependent on ICHV for its replication in primary dog kidney cell cultures (PDK) and was resistant to heating at 70°C for 10 min, and concluded that it was a canine adeno-associated virus (CAAV). Later studies by Onuma and Yanagawa compared CAAV with the known human serotypes (AAV 1, 2, 3) and AAV-4, known to be associated with African Green Monkeys. Using the complement fixation (CF) test, they found that CAAV was serologically related to AAV-3 and had wide distribution in the dog population of Japan.

High Voltage Electron Microscopy of Ion-Milled Dental Enamel

1974 ◽  
Vol 32 ◽  
pp. 60-61
Author(s):  
L. D. Ackerman ◽  
S. H. Y. Wei
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Third Molar ◽  
Polarized Light ◽  
Dental Enamel ◽  
Longitudinal Section ◽  
Ion Milling ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron

Mature human dental enamel has presented investigators with several difficulties in ultramicrotomy of specimens for electron microscopy due to its high degree of mineralization. This study explores the possibility of combining ion-milling and high voltage electron microscopy as a means of circumventing the problems of ultramicrotomy.A longitudinal section of an extracted human third molar was ground to a thickness of about 30 um and polarized light micrographs were taken. The specimen was attached to a single hole grid and thinned by argon-ion bombardment at 15° incidence while rotating at 15 rpm. The beam current in each of two guns was 50 μA with an accelerating voltage of 4 kV. A 20 nm carbon coating was evaporated onto the specimen to prevent an electron charge from building up during electron microscopy.

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

Sign in / Sign up

Export Citation Format

Share Document