Synthesis of Ni/Al(2)O3 catalysts via alkaline polyol method and hydrazine reduction method for the partial oxidation of methane


Bayrakdar Ates E., Gurkaynak Altinckekic T., ÖKSÜZÖMER M. A. F.

TURKISH JOURNAL OF CHEMISTRY, vol.45, no.4, pp.967-985, 2021 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 45 Issue: 4
  • Publication Date: 2021
  • Doi Number: 10.3906/kim-2012-46
  • Journal Name: TURKISH JOURNAL OF CHEMISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Chemical Abstracts Core
  • Page Numbers: pp.967-985
  • Keywords: Alkaline polyol method, hydrazine reduction, nickel, nanoparticles, catalytic partial oxidation of methane, SOLUTION COMBUSTION METHOD, SUPPORTED NI CATALYSTS, SYNTHESIS GAS, NICKEL NANOPARTICLES, HYDROGEN-PRODUCTION, NI/AL2O3 CATALYSTS, PARTICLES, POWDER, COBALT, MORPHOLOGY
  • Istanbul University Affiliated: No

Abstract

Nickel catalysts supported on gamma-Al2O3 were synthesized in the presence of polyvinylpyrrolidone (PVP) using both alkaline polyol method and hydrazine reduction method while fixing the weight ratio of [(PVP)]/[Ni(CH3COO)(2)center dot 4H(2)O] at 2. The effects of hydrazine [N2H5OH]/[Ni] and [NaOH]/[Ni] molar ratios on the structural properties of the catalysts were characterized by transmission electron microscopy (HRTEM) and by X-ray diffraction (XRD). The average of monodispersed Ni nanoparticles ranged between 8.0 and 13.0 nm. The catalytic tests were performed for the partial oxidation of methane in the temperature range of 600-800 degrees C under a flow rate of 157,500 L kg(-1) hr(-1) with CH4/O-2 = 2. At the molar ratio of [NaOH]/[Ni] = 2, the resultant nickel nanoparticles on alumina was established completely without impurities; thus, it demonstrated the highest catalytic activity, 88% for CH4 conversion, and H-2 selectivity, 90.60%. The optimum [N2H5OH]/[Ni] ratio was determined as 4.1, which means a good catalytic performance and 89.35% selectivity to H 2 for the partial oxidation of methane.