Oxidative dehydrogenation of ethane over NiO-loaded high surface area ZrO2 catalysts

  • Prof Na-oki Ikenaga, Department of Chemical, Energy and Environmental Engineering, Kansai University, Japan
  • Mr Kazuki Sakitani, Department of Chemical, Energy and Environmental Engineering, Kansai University, Japan
  • Mr Ken-ichi Nakamura, Department of Chemical, Energy and Environmental Engineering, Kansai University, Japan
  • Prof Takanori Miyake, Department of Chemical, Energy and Environmental Engineering, Kansai University, Japan
  • Dr Toshimitsu Suzuki, Department of Chemical, Energy and Environmental Engineering, Kansai University, Japan

Oxidative dehydrogenation of ethane (ODHE) to ethene, which is major building block in the petrochemical industry, is an attractive alternative to the current steam cracking processes. Since the ODHE is an exothermic reaction, it can be carried out at a lower temperature than the steam cracking process.
The ODHE reactions over POn/NiO/ZrO2 (High Surface area Zirconia: HSZ) catalyst and NiO/HSZ catalyst were carried out with a fix-bed flow reactor at 450 oC under atmospheric pressure without dilution by inert gas at ethane/O2=2/1. In the ODHE, NiO/HSZ catalyst showed ethane conversion of 24.8%, ethene selectivity of 55.6%, and ethene yield of 13.8%. The addition of POn (0.52 wt%) to NiO/HSZ increased the catalytic activity to thane conversion of 32.1%, ethene selectivity of 64.2%, and ethene yield of 20.6%. Moreover, the catalytic activity did not decrease for at least 12 h. In XPS analyses, Ni species of NiO/HSZ catalyst after the reaction exhibited partly reduced metallic Ni. In contrast, in POn/NiO/HSZ, Ni species exhibited mostly the NiO form after the reaction. It was found to be important for high ethane conversion and ethene selectivity, the Ni species not to be reduced to metallic Ni during the ODHE reaction. The addition of a small amount of POn to NiO/HSZ catalyst significantly contributed to the resistance to the facile reduction of NiO.