Correlation between catalytic selectivity and oxygen storage capacity in autothermal reforming of methane over Rh/Ce_(0.45)Zr_(0.45)RE_(.01) catalysts (RE = La, Pr, Nd, Sm, Eu, Gd, Tb)

摘要

Trivalent rare-earth (RE = La, Pr, Nd, Sm, Eu, Gd, Tb)-doped Ce_(0.45)Zr_(0.45)RE_(0.1) solid solutions were synthesized via reverse micro-emulsion method and the catalytic performance of the Rh-supported catalysts was investigated in autothermal reforming of methane (ATR). It was found that CH4 conversion went through a maximum as a function of oxygen storage capacity (OSC) value of the support. Higher OSC will help to enhance the reactivity toward water-gas-shift (WGS) reaction, resulting higher H2/CO ratio. A striking correlation between OSC and H2/CO ratio was observed, which presented a maximum for the Rh/CZLa (3.4) and a minimum for the Rh/CZTb (2.6) catalysts.