Destabilization of NH3BH3 by water during hydrothermolysis as a key factor in the high hydrogen evolution rates
| Autor: | O.V. Netskina, G.V. Odegova, O.V. Komova, N.L. Kayl, V.I. Simagina |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Hydrogen
Renewable Energy Sustainability and the Environment Hydride Inorganic chemistry Thermal decomposition Ammonia borane Energy Engineering and Power Technology chemistry.chemical_element 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 0104 chemical sciences Hydrolysis chemistry.chemical_compound Fuel Technology chemistry Dehydrogenation Reactivity (chemistry) 0210 nano-technology Hydrogen production |
| Zdroj: | International Journal of Hydrogen Energy. 41:17484-17495 |
| ISSN: | 0360-3199 |
| Popis: | The rates of non-catalytic hydrolysis, thermolysis and hydrothermolysis of ammonia borane (NH 3 BH 3 , AB) at 80 °C and 90 °C have been compared. It was found that by using water-wetted AB and carrying out the process of hydrothermolysis results in an order of magnitude increase in the rate of hydrogen generation. The highest rate of AB hydrothermolysis accompanied by a drastic heat-up of the reaction layer was observed at the optimal water content in AB. Carrying out this process in a polyethylene medium which is poor heat conductor resulted in even higher efficiency of the process. On the basis of spectroscopic ATR-FTIR data we conclude that the high reactivity of AB in hydrothermolysis was most likely caused by destabilization of dihydrogen B H δ− – δ+ H N bonds in the NH 3 BH 3 crystal lattice by polar water molecules leading to an increased dispersion of hydride. This increase in dispersion results in enhanced AB reactivity in dehydrogenation and leads to formation of polyaminoborane (PAB). It was shown that PAB which is formed after release of one equivalent of hydrogen is hydrolyzed more easily comparing with starting AB. On the other hand, the products of AB and PAB hydrolysis are believed to be also capable of accelerating AB hydrogenation. |
| Databáze: | OpenAIRE |
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