Support oxide tuning of MnOx-Na2WO4 catalysts enables low-temperature light-off of OCM

The MnO x -Na 2 WO 4 catalyst for oxidative coupling of methane (OCM) is highly attractive but its high light-off temperature (>800 °C) is a major obstacle for commercialization. In-depth understanding of reaction light-off relevant chemistry is particularly desirable. We explored the OCM light-off over several metal-oxide-supported MnO x -Na 2 WO 4 catalysts. As CH 4 conversion above 15% with acceptable C 2-3 selectivity is considered as the sign of OCM light-off, support-dependent OCM light-off is clearly observed over MnO x -Na 2 WO 4 supported on SnO 2 (660 °C), TiO 2 (670 °C), MgO (690 °C), and ZnO (720 °C), being tightly linked with the redox rate of Mn 3+ (or Mn 4+ ) ↔ Mn 2+ cycle governed by support oxides.