Rachid Amrousse

Catalytic decomposition of N2O over Ni and Mg-magnetite catalysts

The total decomposition of N2O was performed on the partially nanocrystalline substituted MxFe3−xO4 magnetite (M2+ = Ni2+ and Mg2+ with x = 0–1). The given results showed that the partial incorporation of Fe2+ by Ni2+ and Mg2+ into Fe3O4 spinel frameworks led to a significant amelioration in the catalytic activity for the N2O catalytic reaction. Furthermore, the catalytic activity of synthesized substrates depended on the Fe2+ substitution amount by Ni2+ and Mg2+ cations. The N2O conversion reached 20% (chemical regime) over the Ni0.75Fe2.25O4 and Mg0.58Fe2.42O4 catalysts at 395 and 404 K for N2O (5000 ppm), respectively. A relative increase of decomposition temperatures was observed after O2 addition. Moreover, other results show that the N2O conversion shifted to higher temperatures at high space velocities.

Novel Rh-substituted hexaaluminate catalysts for N2O decomposition

Novel Rh-substituted hexaaluminate catalysts were prepared for the first time for N2O decomposition as a green propellant. The catalytic tests revealed that an Rh content of x = 0.3 in the BaRhxMn1−xAl11O19 structure is able to decompose N2O from 250 °C and maintain the stability at the adiabatic temperature of 1200 °C.

A Highly Distributed CuxAuy‐Deposited Nanotube Carbon for Selective Reduction of NO in the Presence of NH3 at Very Low Temperature

CuxAuy Deposited on carbon nanotubes prepared by solution plasma sputtering was used for first time as a catalyst for selective reduction of NO, in the presence of NH3, at low temperature. N2 and H2O are desirable during the NO reduction process; however, N2O is totally absent from the obtained products.

Catalytic Decomposition of Ammonium Dinitramide (ADN) as High Energetic Material over CuO-based Catalysts

CuO supported on a La2O3-doped alumina catalyst was prepared and tested in the decomposition process of an ADN–water energetic propellant. The decomposition products were investigated via on-line analysis. Moreover, CuO/Al2O3–La2O3 shows better results of ADN decomposition in comparison with CuO/Al2O3. Both catalysts were characterized by physico-chemical techniques.

Investigation of Сombustion and Thermal Analysis of Ammonium Nitrate with Carbonaceous Materials

ABSTRACT In this article, we present experimental results of the combustion processes and thermal analysis of ammonium nitrate with carbonaceous materials. The thermal analysis was conducted by differential scanning calorimetry to investigate the decomposition of ammonium nitrate with carbonized rice husks and dextran. Differential scanning calorimetry data analysis showed a tendency of lowering the activation energy of the oxidizer in the presence of dextran. The calculated activation energies were in the range of 65–82 kJ/mol. The combustion wave behavior was studied in a high-pressure chamber recorded by a high-speed camera.

Thermal and Catalytic Decomposition of H2O2-Ionic Liquid Monopropellant Mixtures on Monolith-Based Catalysts

The study and development of new monopropellants as hydrazine substitutes for propulsion applications are currently investigated to reduce handling and storage costs and to increase engine performance. The most cited meri t of these new propellants is their reduced toxicity and low vapour pressure and keywords as “non-toxic propellants” or “green propellants” are extensively used in literat ure and proceedings. Aqueous energetic ionic liquids comprising an ionic oxidizer, an ioni c or molecular fuel and water as solvent, are currently proposed and investigated as new monopropellants and possible hydrazine substitutes. The main advantages of these new propellant formulations versus hydrazine are: (i) lower melting points, (ii) higher densities, (i ii) higher volumetric impulses for equivalent specific impulses and (iv) generally accessible on a semi-industrial scale. But different challenges have to be overcome before the practical development and production of new thrusters using these propellants. In the present p aper, A batch reactor has been used to study the thermal and catalytic decompositions of binary aqueous hydroxylammonium nitrate (HAN: [NH 3OH] + [NO 3] ) and ternary aqueous HAN-H2O2 mixtures. The activity of different catalysts has been evaluated by determini ng the reaction products.

Retracted article: A novel approach for N2O decomposition over Rh-substituted hexaaluminate catalysts

We, the authors, Rachid Amrousse, Akimasa Tsutsumi and Ahmed Bachar, hereby wholly retract this Catalysis Science & Technology article. This article has been retracted as it contains significant overlap with the writing in the article, “A novel Ir-hexaaluminate catalyst for N2O as a propellant”, Chem. Commun., 2007, 1695–1697, without sufficient attribution to this earlier work being given. Signed: R Amrousse, A Tsutsumi and A Bachar, November 2013. This retraction is endorsed by Jamie Humphrey, Managing Editor. Retraction published 29 November 2013.

Catalytic Combustion of Hydrogen-Oxygen Cryogenic Mixtures over Cellular Ceramic Based-Catalysts

The catalytic combustion of hydrogen-oxygen mixtures uses catalytically active metals inside the reactor to initiate and stabilize the co mbustion process. Catalytic igniters based on granular beds have been used for many years in small monopropellant rocket thrusters for attitude control of satellites. The use of catalyti c bed combustors made of monolithic cellular ceramics has been previously considered in gas turb ines. There has been also interest in adopting monolithic reactors for the catalytic igni tion of hydrogen-oxygen mixtures for propulsion applications. Monolithic reactors have t he potential of higher performance and longer catalyst life by comparison with pellet-base d catalysts. A cellular ceramic reactor consists of a solid monolith with parallel straight channels (honeycomb type) or more complex channel systems (foam type). On the surface of the internal wall of the channels, a layer of porous material is deposited (wash-coating ). Within the pores of this layer, active phase precursors are impregnated and transformed into active phase (oxidation-reduction process). A well-known example is the use of platin um catalyst on alumina washcoat.