Chronic obstructive lung disease after ammonia inhalation burns: a report of two cases

Anhydrous ammonia is a commonly used chemical in industry. Ammonia gas inhalation causes thermal injuries and alkali burns in the airway and lung parenchyma. Previous case reports have stated that respiratory sequelae after acute ammonia inhalation burns were associated with structural lung disease, such as bronchiectasis or interstitial lung disease. We herein report two cases of long-term sequelae with persistent airflow limitation after ammonia inhalation burns

Preparation of Pt/NiO-C electrocatalyst and heat-treatment effect on its electrocatalytic performance for methanol oxidation

Pt catalyst supported on Vulcan XC-72R containing 5 wt% NiO (Pt/NiO–C) showed larger electrochemical active surface area and higher electrochemical activity for methanol oxidation than Pt catalyst supported on Vulcan XC-72R using polyol method without NiO addition. Prepared Pt/NiO–C electrocatalyst was heat-treated at four temperatures (200, 400, 600, and 800 C) in flowing N2. X-ray diffraction and temperature-programmed desorption results indicated that NiO was reduced to Ni in inert N2 during heat-treatments at temperatures above or equal to 400 C, while oxygen from NiO reacted with carbon support due to the catalytic effect of Pt. The reduced Ni formed an alloy with Pt, which, according to the X-ray photoelectron spectroscopy data, resulted in a shift to a lower binding energy of Pt 4f electrons. The Pt/NiO–C electrocatalyst heat-treated at 400 C showed the best activity in methanol oxidation due to the change in Pt electronic structure by Ni and the minimal aggregation of Pt particles.the Brain Korea 21 Program and by the ERC Program of MOST/KOSEF (Grant No. R11-2002-102-00000-0

Nano-structured Carbon Support for PtC Anode Catalyst in Direct Methanol Fuel Cell

Platinum catalysts for the DMFC(Direct Methanol Fuel Cell) were impregnated on several carbon supports and their catalytic activities were evaluated with cyclic voltammograms of methanol electro-oxidation. To increase the activities of the Pt/C catalyst, carbon supports with high electric conductivity such as mesoporous carbon, carbon nanofiber, and carbon nanotube were employed. The Pt/e-CNF(etched carbon nanofiber) catalyst showed higher maximum current density of 70 mAcm-2 and lower on-set voltage of 0.54 V vs. NHE than the Pt/Vulcan XC-72 in methanol oxidation. Although the carbon namaed by CNT(carbon nanotube) series turned out to have larger BET surface area than the carbon named by CNF(carbon nanofiber) series, the Pt catalyst supported on the CNT series were less active than those on the CNF series due to their lower electric conductivity and lower availability of pores for Pt loading. Considering that the BET surface area and electric conductivity of the e-CNF were similar to those of the Vulcan XC-72, smaller Pt particle size of the Pt/e-CNF catalyst and stronger metal-support interaction were believed to be the main reason for its higher catalytic activity.the Korea Science and Engineering Foundation through the Research Center for Energy Conversion and Storage, and by the Ministry of Science and Technology of Korea through Research Center for Nanocatalysis, one of the National Science Programs for Key Nanotechnolog

The effect of cerium oxide nanoparticles on a Pt/C electrocatalyst synthesized by a continuous two-step process for low-temperature fuel cell

An effective method was developed for preparing highly dispersed CeO2 nanoparticle on a Pt/C catalyst synthesized by a continuous two-step process. From the XRD patterns, the diffraction pattern of the 20Pt–10CeO2/C catalyst revealed that both crystalline Pt and CeO2 phases coexisted. The TEM images show that the Pt and CeO2 nanoparticles were well-dispersed on the surface of the carbon support, which is known to be important for activity in the ORR test. In the ORR and single-cell tests, the 20Pt–10CeO2/C catalyst showed higher performance than a commercial 20Pt/C catalyst, owing to the oxygen storage capacity of CeO2 and its ability to rapidly exchange oxygen with oxygen in the buffer. Keywords: Low-temperature fuel cell, Oxygen reduction reaction, Cathode electrocatalyst, Cerium oxide, Two-step proces

Use of ultrafiltration membranes for the separation of TiO2 photocatalysts in drinking water treatment

This study investigated the ability of cross-flow ultrafiltration (UF), combined with photocatalytic reactions, to separate TiO2 photocatalysts from treated water in photocatalytic drinking water treatment. The effect of natural organic matter (i.e., humic acids) and cross-flow velocities on UF fluxes and organic removal was explored with and without UV irradiation in the photocatalytic reactor. The interaction between the two solutes in the system, humic acids and TiO2 photocatalysts, played a significant role in the formation of dense cake layers at the membrane surface, leading to a greater flux decline during ultrafiltration of TiO2 particles. According to visual observations of the used membranes and the estimation of back-transport velocities of the solutes, a substantial amount of TiO2 deposited on the membrane induces more humic acids to accumulate at the membrane through the adsorption of humic acids onto TiO2 particles. The humic-acid-laden TiO2 particles offered more than four times higher specific cake resistance with a substantially increased compressibility coefficient than TiO2 particles alone. The higher the cross-flow velocities, the greater the UV254 removal achieved. This was because the rise of cross-flow velocities contributed to the reduction of concentration polarization at the membrane surface, thereby resulting in a decrease of the driving force for humic acids to pass through the membrane. When photocatalytic reactions took place with UV illumination, UV254 removal efficiencies of the permeate were improved markedly, and also the permeate flux was kept at a constant level without any sign of fouling. Although humic acids were not completely mineralized by photocatalysis, the degradation of the humic acids helped to enhance the UF flux, as they were transformed to less adsorbable compounds.

Nitrogen-containing graphitized carbon support for methanol oxidation Pt catalyst

Graphitized carbon (GrC) with a relatively uniform pore size was synthesized using polyvinylpyrrolidone as a nitrogen-containing carbon source. Ni was employed as both a graphitization catalyst and a pore structure template. The polyol method was applied to load Pt nanoparticles with a narrow distribution of sizes on the synthesized GrC. The Pt catalyst supported on GrC showed higher electrocatalytic activity than that supported on heat-treated Vulcan XC-72R carbon despite the small specific surface area of GrC. Mass- and areanormalized current densities of Pt/GrC were 2.2 and 3.0 times greater than those for Pt catalyst supported on the commercial carbon, respectively. The better performance of the Pt/ GrC could be due to high electric conductivity and interaction between GrC and Pt nanoparticles resulting from the presence of nitrogen in the prepared GrC.the Brain Korea 21 Program and by the ERC Program of MOST/KOSEF (Grant No. R11-2002-102-00000-0

Preparation of PtRu nanoparticles on various carbon supports using surfactants and their catalytic activities for methanol electro-oxidation

In the anodes of direct methanol fuel cells (DMFCs), Pt poisoning by CO adsorption during methanol electro-oxidation has been a serious problem. Efforts to overcome or minimize this obstacle have largely involved investigations of PtRu bimetallic catalysts. In order to prepare fine PtRu alloyed hydrosols, we used non-ionic surfactants including L121, Pluronic P123, P65, Brij 35, and Tween 20 as stabilizers in this study. The sizes of the prepared metal particles change with the surfactant used. The finest metal hydrosol is obtained when Pluronic P123 and P65 are used. The resulting metal hydrosols with Pluronic P123, Brij 35 and Tween 20 are supported on Vulcan XC-72R. PtRu/XC-72R prepared with Pluronic P123 exhibits the best catalytic activity due to better dispersion of the alloyed metal. To improve further the activity of the PtRu catalyst, the commercial Vulcan XC-72R is replaced with carbon spherule (CS), a home-made carbon support. Electrochemical analyses such as cyclic voltammetry and galvanostatic-polarization tests are performed to evaluate the prepared catalyst. PtRu/CS has a superior performance to PtRu/XC-72R in methanol electro-oxidation when Pluronic P123 is employed as the stabilizer. The higher conductivity and larger inter-particle space of the CS appear to facilitate methanol electro-oxidation.the ERC Program of MOST/KOSEF (Grant No. R11-2002-102-00000-0), and by the Ministry of Science and Technology of Korea through the Research Center for Nanocatalysis, one of the National Science Programs for Key Nanotechnolog

Effect of lithium carbonate on nickel catalysts for direct internal reforming MCFC

Despite many advantages of the direct internal reforming molten carbonate fuel cell (DIR-MCFC) in producing electricity, there are many problems to solve before practical use. The deactivation of reforming catalyst by alkali like lithium is one of the major obstacles to overcome. A promising method is addition of TiO2 into the Ni/MgO reforming catalyst, which resulted in the increased resistance to lithium poisoning as we previously reported. To understand how added titania worked, it is necessary to elucidate the deactivation mechanism of the catalysts supported on metal oxides such as MgO and MgO–TiO2 composite oxide. Several supported nickel catalysts deactivated by lithium carbonate were prepared, characterized and evaluated. The Ni/MgO catalyst turned out to be most vulnerable to lithium deactivation among the employed catalysts. The activity of the Ni/MgO gradually decreased to zero with increasing amount of lithium addition. Deactivation by lithium addition resulted from the decrease of active site due to sintering of nickel particles as well as the formation of the LiyNixMg1−x−yO ternary solid solution. These were evidenced by H2 chemisorption, temperature programmed reduction, and XRD analyses. As an effort to minimize Li-poisoning, titanium was introduced to MgO support. This resulted in the formation of Ni/Mg2TiO4, which seemed to increase resistance against Li-poisoning.the Korea Electric Power Research Institute through the Korea Institute of Science and Technology, and by the Korea Science and Engineering Foundation through the Research Center for Energy Conversion and Storag