Bimetallic RuCo and RuCu catalysts supported on γ-Al2O3. A comparative study of their activity in hydrolysis of ammonia-borane
| Autor: | Umit B. Demirci, Philippe Miele, Giovanni P. Rachiero |
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| Přispěvatelé: | Institut Européen des membranes (IEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM) |
| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Reaction mechanism
Order of reaction Renewable Energy Sustainability and the Environment Chemistry Stereochemistry Ammonia borane Energy Engineering and Power Technology 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Heterogeneous catalysis 01 natural sciences 0104 chemical sciences Catalysis chemistry.chemical_compound Fuel Technology [CHIM]Chemical Sciences Dehydrogenation 0210 nano-technology Bimetallic strip Ethylene glycol ComputingMilieux_MISCELLANEOUS Nuclear chemistry |
| Zdroj: | International Journal of Hydrogen Energy International Journal of Hydrogen Energy, Elsevier, 2011, 36 (12), pp.7051-7065. ⟨10.1016/j.ijhydene.2011.03.009⟩ |
| ISSN: | 0360-3199 |
| DOI: | 10.1016/j.ijhydene.2011.03.009⟩ |
| Popis: | Bimetallic-based RuCo and RuCu catalysts, supported on γ-Al2O3 (1.5 wt% Ru as theoretical value), were synthesized by polyol method. Ru, Co, and Cu acetylacetonates were used as precursors and ethylene glycol as reducing agent. The as-synthesized catalysts were characterized by SEM, TEM, XRD and XPS, and tested in ammonia-borane (NH3BH3) hydrolytic dehydrogenation at variable amount of catalyst (10–30 wt%), concentration of NH3BH3 (1.0–0.65 M), and temperatures (50–65 °C). The reactions were monitored by volumetric (inverted burette) and spectroscopic methods (11B and 11B{1H} NMR). It was found that the best bimetallic catalysts are those having a molar ratio Ru:Co and Ru:Cu of 1:1 such as RuCo > RuCu ∼ Ru. They, i.e. RuCo and RuCu, consist of nanosized spherical particles of Ru0Co(OH)2 and Ru0Cu0, respectively. Kinetic investigation highlights similar rate laws with activation energies of 47 kJ mol−1 and 52 kJ mol−1, respectively, and, for both, reaction orders of 1 versus both the NH3BH3 and the catalytic free sites concentrations. 11B and 11B{1H} NMR investigation confirmed (i) a more effective NH3BH3 hydrolytic dehydrogenation in the presence of RuCo catalyst even though a loss of activity after the first run was observed for both catalysts, and (ii) a rapid NH3BH3 hydrolysis with initial formation of B(OH)4−, which besides favors equilibriums of formation of polyborates. These results are reported and the reaction mechanism discussed herein. |
| Databáze: | OpenAIRE |
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