Ammonia, hydrogen generation from

Some 2,4,6-triaryl-l,3,5-triazincs 1 can be converted to triaryl-substituted imidazoles 2 by reduction with nascent hydrogen generated from zinc in acetic acid or zinc in potassium hydroxide (see Houben-Weyl, Vol. E8c, p 93). In this reaction one nitrogen is lost in the form of ammonia. The reaction times required arc between 20 minutes and two hours in hot acetic acid15 or refluxing aqueous potassium hydroxide 16 the yields are reported to be nearly quantitative.13 17... 

Lu, Z.-H. Yao, Q. Zhang, Z. Yang, Y Chen, X, Nanocatalysts for Hydrogen Generation from Ammonia Borane and Hydrazine Borane. Journal of Nanomaterials 2014,2014,11. 

To address this problem, Xu et al. synthesized dendrimer-encapsulated Co nanoparticles, (Gg-OH(Cogo)) with narrow size distribution (1.6 0.4 nm), by using hydroxyl-terminated poly (amidoamine) dendrimer of generation six [42], and they investigated its catalytic activity for hydrolysis of ammonia borane. The results indicated that hydrogen generation from room temperature... 

Gg-OHCCoso)) catalyzed hydrolysis of ammonia borane was 3 equiv (Fig. 6.31). This is the complete hydrogen generation from hydrosis of ammonia borane according toEq. 6.1. 

Another path to hydrogen generation from ammonia works with magnesium hydride over homogeneous platinum and palladium chloride catalysts [103] ... 

TRANSITION METAL NANOPARTICLES CATALYST IN HYDROGEN GENERATION 173 TABLE 7.2 Transition Metal Nanoparticles Catalysts Used in Hydrogen Generation from the Hydrolysis of Ammonia Borane Activation Energy of the Catalytic Hydrolysis and Activity of Catalyst in Turnover Frequency (TOF) at 25 °C, —Not Reported ... 

TRANSITION METAL NANOPARTICLES CATALYSTS IN HYDROGEN GENERATION FROM THE METHANOLYSIS OF AMMONIA BORANE ... 

Kalidindi, S. B. Sanyal, U. Jagirdar, B. R., Nano structured Cu and CuOCujO core shell catalysts for hydrogen generation from ammonia-borane, Phys. Chem. Chem. Phys. 2008,10, 5870-5874. 

Bluhm ME et al (2006) Amineborane-based chemical hydrogen storage enhanced ammonia borane dehydrogenation in ionic liquids. J Am Chem Soc 128 7748-7749 Chandra M, Xu Q (2007) Room temperature hydrogen generation from aqueous ammonia borane using noble metal nanoclusters as highly active catalysts. J Power Sources... 

Amines, like ammonia, are weak bases (see p. 31) and dissociate to a slight extent in aqueous solution. In the reaction, the non-bonded pair (lone pair) of electrons on the nitrogen atom in the amine molecule accepts a proton (hydrogen ion) from the water molecule, thus generating alkylammonium ions and hydroxide ions. The latter ions make the solution alkaline. For example CHjNH aq) H20(l) CH3NH3 (aq) -r OH (aq)... 

Metal Hydride Process for Ammonia Purge Gas, The metal hydride process will be illustrated using the case of hydrogen recovery from an ammonia purge gas stream generated during ammonia manufacture. 

Heal from the external source is supplied to the generator, where a mixture of ammonia and water vapor with drops of ammoniated water is raised to the separator in the same manner as water is raised to the coffee in a percolator, Ammonia vapor escapes from the liquid in the separator and rises to the condenser, where it cools and liquefies. Before the liquefied ammonia enters the evaporator, hydrogen, rising from the absorber, mixes with it and aids in the evaporation process. Finally, the mixture of hydrogen and ammonia vapor enters the absorber, where water from the separator dissolves the ammonia. The ammonia water returns to the generator to complete the cycle. In this cycle, heat enters the system nut only at the generator, but also at the evaporator, and heal leaves (lie system at both the condenser and the absorber to enter the atmosphere by means of radiating fins. 

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