Catalysis of methane coupling with carbon dioxide over binary oxides
- 化学化工－已发表论文 
Binary oxides of Ca-Ce, Ca-Cr, and Ca-Mn exhibit good performance and similar kinetic behavior in the conversion of CH4 to C-2 hydrocarbons with CO2, whereas the corresponding Sr- and Ba-containing catalysts show lower activity in C-2 formation except for Sr-Mn and Ba-Mn oxides. The Sr-Mn oxide provides even higher C-2 yield than the Ca-containing catalysts. Characterization reveals that solid solution and composite oxides comprising Ca2+ species and the redox component (Ce, Cr, or Mn) exist at a steady state of reaction and probably account for the synergy in C-2 formation over the Ca-containing catalysts. On the other hand, Sr and Ba carbonates are formed along with Ce, Cr, or Mn oxides during the reactions over Sr- and Ba-containing oxides. The carbonates, however, can react with MnO to form SrMnO2.5 and BaMnO2.5, the probable active species for CH4 activation over the Sr-Mn and Ba-Mn catalysts.