Systematic Study of Pt-Ru/C Catalysts Prepared by Chemical Deposition for Direct Methanol Fuel Cells

Abstract

In this research, the activity and stability for methanol electro-oxidation on Pt-Ru/C catalysts was increased by optimising the catalyst preparation method. The Pt-Ru/C catalysts were synthesised using Pt(acac) 2 and Ru(acac) 3 precursors for chemical deposition of the metals. Performance of the catalyst was examined by cyclic voltammetry and chronoamperometry in a methanolcontaining electrolyte. TEM, EDS, X-ray photoelectron spectroscopy and XRD were used to physically characterise the catalysts. The parameters investigated were precursor decomposition phase, synthesis temperature and Pt/Ru ratio. Precursor deposition from the liquid phase was more active for methanol electro-oxidation, predominantly due to particle size and degree of alloying achieved during this precursor decomposition phase. Synthesis temperature affected the particle size, active surface area, ruthenium oxidation state and degree of alloying which in turn affected catalyst stability and activity for methanol electro-oxidation. The Pt/Ru ratio greatly affects the performance of the catalyst. The catalyst with the highest activity for methanol electro-oxidation was the catalyst synthesised at 350°C with a Pt/Ru ratio of 50:50.

Evaluation of functional layers thinning of high temperature polymer electrolyte membrane fuel cells after long term operation

“…It has been reported that alloying Pt with Ru enhances notably the CO tolerance by two different effects, namely the electronic and the bifunctional effect. 9 In the electronic effect, Ru modifies the band structure of Pt, reducing its affinity towards CO, while in the bifunctional Ru helps in the catalysis of CO oxidation to CO 2 , which has a lower affinity for the catalyst.…”

Platinum nanoparticles coated by graphene layers: A low-metal loading catalyst for methanol oxidation in alkaline media

“…As hybrid automobiles embrace methanol fuel [1] , the methanol oxidation process is becoming more attractive for next-generation energy conversion systems [2] . However, the development of cheaper, stable catalysts with high performance in methanol oxidation reaction (MOR) is impeded by issues such as the necessity of using transition metals from the platinum group, ruthenium (Ru), iridium (Ir), palladium (Pd), platinum (Pt), or the poisoning of the Pt surface by carbon monoxide (CO) [3][4][5][6][7] . Nevertheless, as in the case of H 2 proton-exchange membrane fuel cells [8] , in certain conditions (e.g., low amounts of platinum on anode and cathode catalysts), the methanol fuel cell costs could be made manageable for large scale commercialization.…”

Synthesis of PtCoNiRu/C nanoparticles by spray drying combined with reduction sintering for methanol electro-oxidation

“…Fuel cells, as clean and renewable energy conversion devices, have become a subject of extensive research interest due to their high power density, high energy efficiency, low operating temperature, and easy storage and transportation. [1][2][3] So far, Ptbased materials are considered to be the most effective electrocatalysts for fuel cells. However, Pt is scarce and expensive, and the kinetics of small organic molecule electro-oxidation on Pt is still relatively sluggish.…”

“…Ni and Co alloyed with Pt to increase the electrocatalytic activity, 26 and Ru improved the anti CO poisoning performance. 3 PtCoNiRu quaternary alloy NPs were synthesized and evenly dispersed on the modified Vulcan XC-72 surface with high loading capacity by spray drying combined with reduction sintering. The inner structure and the electrochemical activities for MOR of the as-synthesized alloy NPs were investigated.…”