Synthesis and characterization of Cu-Cr-O nanocomposites

Abstract

Cu-Cr-O nanocomposites that can be used as additives for the catalytic combustion of AP(ammonium perchlorate)-based solid-state propellants were synthesized via a citric acid(CA) complexing approach. Techniques of TG-DTA, XRD as well as TEM were employed to characterize the thermal decomposition procedure, crystal phase, micro-structural morphologies and grain size of the as-synthesized materials respectively. The results show that well-crystallized Cu-Cr-O nanocomposites can be produced after the CA-Cu-Cr precursors are calcined at 500°C for 3 h. Phase composition of the as-obtained Cu-Cr-O nanocomposites depends on the molar ratio of Cu to Cr in the starting reactants. Addition of the as-synthesized Cu-Cr-O nanocomposites as catalysts enhances the burning rate as well as lowers the pressure exponent of the AP-based solid-state propellants considerably. Noticeably, catalyst with a Cu/Cr molar ratio of 0.7 exhibits promising catalytic activity with high burning rate and low pressure exponent at all pressures, due to the effective phase interaction between the spinel CuCr₂O₄ and delafossite CuCrO₂ contained in the as-synthesized Cu-Cr-O nanocomposites.

Keywords

copper chromite composite / nanomaterial / citric acid / solid-state propellant / catalyst / complexing

References

[1] AdkinsH., ConnorR.. The catalytic hydrogenation of organic compounds over copper chromite[J]. J Am Chem Soc, 1931, 53(3): 1091-1095

[2] ConnorR., FolkersK., AdkinsH.. The preparation of copper-chromium oxide catalysts for hydrogenation[J]. J Am Chem Soc, 1932, 54(3): 1138-1145

[3] ThomasW., RienerW.. An improved laboratory preparation of copper-chromium oxide catalyst[J]. J Am Chem Soc, 1949, 71(3): 1130-1130

[4] RoyS., GhoseJ.. Synthese and studies on some copper chromite spinel oxide composites[J]. Materials Research Bulletin, 1999, 34(7): 1179-1186

[5] StefanescuM., SascaV., MracecM.. Investigation concerning the mechanism and kinetics of copper(II) chromite formation[J]. Revue Roumaine de Chimie, 2000, 45(12): 1063-1068

[6] KhasinaV., SimentsovaI. I., YurévaT. M.. Moderatetemperature reduction of copper chromite by hydrogen and hydrogen desorption from the surface of reduced chromite[J]. Kinetics and Catalysis, 2000, 41(2): 282-286

[7] PrasadR.. Highly active copper chromite catalyst produced by thermal decomposition of ammoniac copper oxalate chromate[J]. Materials Letters, 2005, 59(29/30): 3945-3949

[8] CominoG., GervasiniA., RagainiV.. Methane combustion over copper chromite catalysts[J]. Catalysis Letters, 1997, 48(1/2): 39-45

[9] XanthopoulouG., VekinisG.. Investigation of catalytic oxidation of carbon monoxide over a Cu-Cr-oxide catalyst made by self-propagating high-temperature synthesis[J]. Applied Catalysis B: Environmental, 1998, 19(1): 37-44

[10] ZhaoF., LiG., LiY. N., et al.. Influence of phase-to-phase interaction between CuCrO₂ and CuCr₂O₄ on their structure and catalytic activity[J]. Chinese Journal of Catalysis, 2003, 24(1): 11-16

[11] KawamotoA. M., PardiniL. C., RezendeL. C.. Synthesis of copper chromite catalyst[J]. Aerospace Sci Technol, 2004, 8(7): 591-598

[12] JacobsP. W. M., WhiteheadH. M.. Decomposition and combustion of ammonium perchlorate[J]. Chem Rev, 1969, 69(4): 551-590

[13] RajeevR., DeviK. A., AbrahamA., et al.. Thermal decomposition studies(Part 19): Kinetics and mechanism of thermal decomposition of copper ammonium chromate precursor to copper chromite catalyst and correlation of surface parameters of the catalyst with propellant burning rate[J]. Thermochimica Acta, 1995, 254(15): 235-247

[14] PatronL., PocolV., CarpO., et al.. New synthetic route in obtaining copper chromite(I): Hydrolysis of some soluble salts[J]. Mater Res Bull, 2001, 36(7/8): 1269-1276

[15] StroupeJ. D.. An X-ray diffraction study of the copper chromites and of the “copper-chromium oxide” catalyst[J]. J Am Chem Soc, 1949, 71(2): 569-572

[16] ArmstrongR. W., BaschungB., BoothD. W., et al.. Enhanced propellant combustion with nanoparticles[J]. Nano Letters, 2003, 3(2): 253-255

[17] BaschungB., GruneD., LichtH. H., et al.KuoK. K., DelucaL. T., et al.Combustion of Energy Materials[M], 2001, New York, Begell House

[18] LiW.. Synthesis and catalytic characteristics of Bi₂O₃/Cu-Cr-O core/shell structured nano-composites[J]. Journal of Central South University: Science and Technology, 2006, 37(6): 1019-1024

[19] LiW.. Preparation and structure characteristics of nano-Bi2O3 powders with mixed crystal structure[J]. J Cent South Univ Technol, 2005, 12(3): 243-245