Investigating the Effect of CuO/NiO and CuO/CoO Relative Composition on the Reduction Time of (CuO)x-(NiO)(1-x) and (CuO)x-(Co3O4)(1-x) with Methane Gas as the Reducing Agent in the Synthesis of Nano-bimetallic Nix-Cu(1-x) and Cux-Co(1-x)

Abstract

In this paper, the reduction duration of (CuO)_x-(NiO)_(1-x) and (CuO)_x-(Co3O4)_(1-x) binary mixtures was studied using thermogravimetric method. The reduction reaction was performed using copper, nickel and cobalt oxides as metal precursors and methane gas as the reducing agent, under atmospheric pressure. The products as well as the raw materials were characterized and analyzed using X-Ray diffraction (XRD) and Energy Dispersive Spectroscopy (EDS). Initially, CoO, NiO and CuO were transformed to Co, Ni and Cu through reduction reactions with 23 Vol.% of methane at 830 °C. Results demonstrated that the reduction times of NiO, CoO and CuO NPs with CH₄ at 830 °C were 14, 39 and 47 min, respectively. EDS and XRD analysis indicated that more than 97 % of copper, nickel and cobalt oxides were transformed to copper, nickel and cobalt NPs. The reaction time of (CuO)_x-(NiO)_(1-x) and (CuO)_x-(Co₃O₄)_(1-x) binary mixtures with methane was investigated to evaluate the effect of CuO (x=0, 0.4, 0.6, 1) relative composition. In addition, the reaction time of ternary mixture of (NiO)_0.6-(CuO)_0.2-(Co₃O₄)_0.2 with methane gas was also studied.