Abstract:
This work was carried out to study the CO tolerance of Pt/C catalyst by the addition of H3PMo12O40 and CsxH3-xPMo12O40 (x = 1, 2, 2.5 or 3) for hydrogen oxidation reaction in the presence of 100 ppm CO in PEM fuel cell and for methanol oxidation in H2SO4-CH3OH solution. The work was separated into 2 parts. For the first part, the effect of H3PMo12O40 loading (200-400 wt%) on CO tolerance under 100 ppm CO:H2 and O2 was studied. The results showed that 300 wt% H3PMo12O40 on Pt/C (H3PMo12O40(300)-Pt/C) exhibited the CO tolerance greater than Pt/C catalyst by 1.65-fold because the existence of molybdenum in heteropoly acid structure enhanced CO oxidation. For the second part, the replacement of H+ by the Cs+ in the H3PMo12O40 structure was studied. It was found that the CsxH3-xPMo12O40(300)-Pt/C catalysts had a lower water solubility than the H3PMo12O40(300)-Pt/C catalysts. The Cs1H2PMo12O40(300)-Pt/C showed the CO tolerance greater than Pt/C catalyst both in the solution of H2SO4-CH3OH and in PEM fuel cell in the presence of CO.