STRUCTURAL CHARACTERIZATION AND ELECTROCHEMICAL PERFORMANCE OF MO_4O_(11)AND PT-BLACK COMPOSITE USED FOR METHANOL OXIDATION

摘要

Crystallized Magnéli phase Mo_4O_(11) has been used as a cocatalystsrnsupport mixed with Pt-black to enhance methanol oxidationrnreaction (MOR). It was also found that various valence states ofrnMo(Ⅳ), Mo(Ⅴ), Mo(Ⅵ) co-existed in Mo_4O_(11), which could fastenrnhydrogen spillover and oxygen buffering. These effects collectivelyrncontribute to improving the poisoning tolerance and electrocatalyticrnactivity of Pt/Mo_4O_(11) catalyst towards MOR. The ratio between thernforward peak current to the back peak current (I_f/I_b) is 1.21 and 0.81rnfor the Pt/ Mo_4O_(11) and Pt/C, respectively. The quasi-two-dimensionalrncrystallized Mo_4O_(11) is beneficial to enhance catalytic activityrnbecause of its high electron conductivity. The forward peak currentrn(I_f) of Pt/ Mo_4O_(11) (722.20 mA×mg~(-1)Pt) was 2times higher than thatrnof Pt-black (356.10 mA×mg~(-1)Pt). The results demonstrate that therncrystallized Magnéli phase Mo_4O_(11) is a promising co-catalyst supportrnfor MOR, although its stability remains to be improved.