CO-Tolerant PtMo/C Fuel Cell Catalyst for H₂Oxidation

Abstract

CO-tolerant PtMo/C alloy electrocatalyst was prepared by a colloidal method, and its electrocatalytic activity toward CO oxidation was investigated. Electrochemical study revealed that the alloy catalyst significantly enhanced catalytic activity toward the electro-oxidation of CO compared to Pt/C counterpart. Cyclic voltammetry suggested that Mo plays an important role in promoting CO electro-oxidation by facilitating the formation of active oxygen species. The effect of Mo on the electronic structure of Pt was investigated using X-ray absorption spectroscopy to elucidate the synergetic effect of alloying. Our in-depth spectroscopic analysis revealed that CO is less strongly adsorbed on PtMo/C catalyst than on Pt/C catalyst due to the modulation of the electronic structure of Pt d-band. Our investigation shows that the enhanced CO electrooxidation in PtMo alloy electrocatalyst is originated from two factors; one comes from the facile formation of active oxygen species, and the other from the weak interaction between Pt and CO.

Tolerance of platinum clusters to CO poisoning induced by molybdenum doping

“…Comparing the pure and Mo doped platinum clusters, the Mo doped clusters are expected to be slightly colder after attachment of the first CO molecule because of likely reduction in the binding energy upon doping. 13 Since the Pt n + and Pt n-1 Mo + clusters are produced under the same source conditions (except for the above remark on the temperature after the absorption of the first CO molecule), the changes of S 1 and S 2 upon doping allow to qualitatively characterize the effect of Mo doping on CO tolerance of platinum clusters. In particular, the decrease of S 2 upon doping the Pt n + cluster with Mo (Fig.…”

Reformate gas composition and pressure effect on CO tolerant Pt/Ti0.8Mo0.2O2–C electrocatalyst for PEM fuel cells

“…Molybdenum (Mo) was utilized for CO-tolerant electrocatalyst due to relatively low cost and good catalytic activity of PtMo alloy [12][13]. Mo provides necessary OH ad species for the electrooxidation of CO ad at less positive potentials than Pt (according to "bifunctional mechanism") [14].…”

Development of Hydrogen–Oxygen Fuel Cells Based on Anion-Exchange Electrolytes and Catalysts with Reduced Platinum Content

“…Therefore, reducing the platinum content is considered as a more promising approach to the development of affordable and stable HOR catalysts, rather than developing systems based on other platinum group metals. Molybdenum attracts the attention of researchers due to its relatively low cost, as well as catalytic activity comparable to PtRu, in HOR [ 13 ]. It was shown in [ 14 ] that alloying platinum with molybdenum increases both its catalytic activity and stability in the reaction of hydrogen oxidation in fuel cells.…”