The Experts below are selected from a list of 40584 Experts worldwide ranked by ideXlab platform
Maasoumeh Jafarpour - One of the best experts on this subject based on the ideXlab platform.
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ZrCl4 dispersed on dry silica gel provides a useful reagent for S-alkylation of thiols with alcohols under solvent-free conditions
Tetrahedron Letters, 2006Co-Authors: Habib Firouzabadi, Nasser Iranpoor, Maasoumeh JafarpourAbstract:Abstract ZrCl 4 which is commercially available and not a costly compound, is a relatively Safe Chemical [LD 50 [ZrCl 4 , oral rat] = 1688 mg Kg]. In this report we describe the use of ZrCl 4 dispersed on dry silica gel as an efficient reagent for the efficient preparation of thioethers from thiols with alcohols under solvent-free conditions.
Michael Inde - One of the best experts on this subject based on the ideXlab platform.
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an ultraSafe hydrogen generator aqueous alkaline borohydride solutions and ru catalyst
Journal of Power Sources, 2000Co-Authors: Steve C Amendola, Stefanie Sharpgoldma, Saleem M Janjua, Michael T Kelly, Phillip J Petillo, Michael IndeAbstract:Abstract A novel, simple, convenient, and Safe Chemical process generates high purity hydrogen gas on demand from stable, aqueous solutions of sodium borohydride, NaBH4, and ruthenium-based (Ru), catalyst. When NaBH4 solution contacts Ru catalyst, it spontaneously hydrolyzes to form H2 gas and sodium borate, a water-soluble, inert salt. When H2 is no longer required, Ru catalyst is removed from the solution and H2 generation stops. Since this H2 generator is Safer, has quicker response to H2 demand, and is more efficient than commonly used H2 generators, it is ideal for portable applications.
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an ultraSafe hydrogen generator aqueous alkaline borohydride solutions and ru catalyst
ACS Division of Fuel Chemistry Preprints, 1999Co-Authors: Steve C Amendola, Stefanie Sharpgoldma, Saleem M Janjua, Michael T Kelly, Phillip J Petillo, Michael IndeAbstract:A novel, simple, convenient, and Safe, Chemical process generates high purity hydrogen gas on demand from stable, aqueous solutions of sodium borohydride, NaBH,, and ruthenium based (Ru), catalyst. When NaBH, solution contacts Ru catalyst, it spontaneously hydrolyzes to form H, gas and sodium borate, a water-soluble, inert salt. When H, is no longer required, Ru is removed from the solution and H, generation stops. Since this H, generator is Safer, has quicker response to H, demand, and is more efficient, than commonly used H, generators, it is ideal for portable applications. INTRODUCTION PEM fuel cells are attractive power sources for providing clean energy for transportation and personal electronics applications where low system weight and portability are important. For powering these systems, H, gas is the environmentally desirable anodic fuel of choice since only water is formed as a discharge product. A major hurdlc is how to gcnerate/store controlled amounts of H, fuel directly without resorting to high temperature reformers with significant heat signatures or bulky, pressurized cylinders. Background of the Borohydride H, Generator Our Safe, portable H, generator overcomes these problems by using aqueous, alkaline, sodium borohydride (NaBH,, tetrahydroborate) solutions which are extremely stable. However, as found by Schlesinger et al. ( I ) , in the presence of selected metal (or metal boride) catalysts, this solution hydrolyzes to yield H, gas and water-soluble, sodium metaborate, NaBO,. NaBH, + 2 H,O ----> 4 H, + NaBO, P I catalyst This hydrolysis reaction occurs at different rates depending on the catalyst used and its preparation method. Levy et al. (2) and Kaufman and Sen (3) investigated cobalt and nickel borides as catalysts for practical, controlled generation of H, from NaBH, solutions. We studied ruthenium (Ru) based catalyst supported on ion exchange resin beads. Using Ru is based on the work or Brown and Brown (4). who investigated various metal salts and found that ruthenium and rhodium salts liberated H, most rapidly from borohydride solutions. We chose Ru because of its lower cost. Ru catalysts are not consumed during hydrolysis and are reusable. We have designed our system so that reaction [ I ] is either selfregulating or carefully controllable. To generate H,, NaBH, solution is allowed to flow onto a Ru catalyst, or NaBH, solution is injected onto Ru catalyst. This ensures fast response to H, demand i.e. H, is generated only when NaBH, solution contacts Ru catalyst. When H, is no longer needed, NaBH, solution is removed from Ru catalyst and H, production ceases. With molecular weights of NaBH, (38) and 2 H,O (36), forming 41-1, (8), reaction [ I ] has a I-l,storage efficiency of 8/74 = 10.8%. In addition to H,, the other discharge product, NaBO,, commonly found in laundry detergents, is Safe. Unlike phosphates, borates are not environmentally hazardous in water supplies. Table I compares operational and Safety features of generating H, via base-stabilized NaBH, solutions and via reactive Chemical hydrides. Our generator is considerably Saferhore efficient than producing H, via other reactive Chemicals. The heat generated by our system (75 kJ/mole H, fomied), is less than what is produced by other hydrides (>I25 kJ/mole H,), and ensures a Safe, controllable Chemical reaction. The total amount of H, produced by reaction [ I ] depends on NaBH, solution volume and concentration. H, generation rates are primarily a function of Ru catalyst active surface area. H, pressure/flow rates can be accurately controlled and made self-regulating by numerous feedback
S. F. Solov'ev - One of the best experts on this subject based on the ideXlab platform.
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Reliable inhibition of corrosion of metals : The basis for Safe Chemical cleaning of equipment
Thermal Engineering, 1999Co-Authors: N. I. Shadrina, S. F. Solov'evAbstract:Several problems in organizing Chemical cleaning of the equipment at power stations and in simplifying processes and methods for cleaning caused by changes in the conditions of operation of the equipment are discussed. Special attention is focused on the necessity of reliable inhibition of corrosion of the boiler metals and on the possibility of solving this problem today, which is the most important condition for Safe Chemical cleaning of the equipment.
Masakazu Anpo - One of the best experts on this subject based on the ideXlab platform.
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preparation characterization and reactivities of highly functional titanium oxide based photocatalysts able to operate under uv visible light irradiation approaches in realizing high efficiency in the use of visible light
Bulletin of the Chemical Society of Japan, 2004Co-Authors: Masakazu AnpoAbstract:A review of the research advances made in the design and development of highly reactive and functional titanium oxide photocatalysts, which can utilize not only UV but also visible or solar light, and a clarification of the active sites as well as the detection of the reaction intermediates at the molecular level have been presented here. The potential for the effective utilization and conversion of solar energy into useful and Safe Chemical energy by the modification of the electronic properties of such TiO 2 photocatalysts is great when one considers their myriad applications as well as their nonpolluting qualities. Such a modification process by methods such as ion-implantation can be applied not only for semiconducting bulk TiO 2 photocatalysts but also for TiO 2 thin film photocatalysts and titanium oxide photocatalysts highly dispersed within zeolite frameworks. Moreover, the photocatalytic reactivity of semiconducting TiO 2 nano-powders was found to be dramatically enhanced by the loading of small amounts of Pt. This worked to enhance the reduction reaction, resulting in the charge separation of the electrons and holes generated by light irradiation. In addition, highly dispersed titanium oxide species prepared within zeolite frameworks as well as SiO 2 or Al 2 O 3 matrices showed much higher and unique photocatalytic performances as compared to semiconducting bulk TiO 2 photocatalysts. Significantly, a new alternative method to directly prepare such visible light-responsive TiO 2 thin film photocatalysts on various substrates has been successfully developed by applying a RF magnetron sputtering deposition method.
Habib Firouzabadi - One of the best experts on this subject based on the ideXlab platform.
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ZrCl4 dispersed on dry silica gel provides a useful reagent for S-alkylation of thiols with alcohols under solvent-free conditions
Tetrahedron Letters, 2006Co-Authors: Habib Firouzabadi, Nasser Iranpoor, Maasoumeh JafarpourAbstract:Abstract ZrCl 4 which is commercially available and not a costly compound, is a relatively Safe Chemical [LD 50 [ZrCl 4 , oral rat] = 1688 mg Kg]. In this report we describe the use of ZrCl 4 dispersed on dry silica gel as an efficient reagent for the efficient preparation of thioethers from thiols with alcohols under solvent-free conditions.
