Particle size and alloying effects of Pt-based alloy catalysts for fuel cell applications

1.Introduction
2.X-ray Absorption Spectroscopy
2.1. XANES
2.2. EXAFS
3.Data Collection and In Situ Cells
4.XAS as a Characterization Method: Pt/C
4.1. Particle Size
4.2. Potential Dependence
4.3. Adsorbates
5.Pt Containing Alloy Catalysts
5.1. PtRu Alloys
5.1.1. Compositional Analysis
5.1.2. Potential Dependence
5.1.3. Adsorbates
5.2. Other Pt Containing Alloy Anode Catalysts
5.3. Pt Containing Alloy Cathode Catalysts
6.Non-Pt Catalysts
7.Conclusion
8.References

X-ray absorption spectroscopy of low temperature fuel cell catalysts.

http://gecea.ist.utl.pt/Publications/JRS/P06_salgado_IJHE_2005.pdf

Effects of geometric and electronic factors on ORR activity of carbon supported Pt-Co electrocatalysts in PEM fuel cells

Electrocatalysis of oxygen reduction on a carbon supported platinum–vanadium alloy in polymer electrolyte fuel cells

A novel flow battery: A lead acid battery based on an electrolyte with soluble lead(II): Part VII. Further studies of the lead dioxide positive electrode

In situ studies of a dispersed platinum on carbon electrode using X-ray absorption spectroscopy

As an integral part of a program to develop x‐ray techniques for in situ structural studies of electrode surfaces, a series of experiments has been carried out using x‐ray diffraction (XRD) and x‐ray absorption spectroscopy (XAS) at the Daresbury SRS. These studies, which involve continuous control of the electrode potential and the need to probe the electrode surface with synchrotron radiation, demand careful attention to cell design. Three types of experiment are described in order to illustrate possible approaches to cell design and the versatility of in situ x‐ray techniques.

Instrumentation and cell design for in situ studies of electrode surfaces using x‐ray synchrotron radiation

X‐ray diffraction and absorption spectroscopy provide complementary structural tools for the in situ characterization of electrode surfaces. To optimize surface sensitivity, techniques such as glancing angle scattering geometries and spectrum differencing can be employed while the application of synchrotron radiation allows the real‐time collection of data. This paper outlines recent developments in in situ electrochemistry on the Daresbury SRS and describes an electrochemical cell for in situ x‐ray studies, associated glancing angle instrumentation, together with computer hardware and software optimized for data acquisition using potential modulation techniques. Important fundamental and industrial applications are highlighted.

Instrumentation and data acquisition for in situ electrochemistry at the Daresbury SRS

The development of a new integrated materials science facility (station 9.3) on the wiggler line of the Daresbury Synchrotron Radiation Source is outlined. The facility combines instrumentation for data acquisition using both spectroscopic (XANES and EXAFS) and diffraction techniques and is optimized towards industrial applications such as catalysis and electrochemistry using in situ techniques.

Integrated materials science facility on the SRS

Changes in the phase composition of lead dioxide deposited on platinum have been studied via an in-situ X-ray diffraction technique using synchrotron radiation. The lead dioxide was deposited from an aqueous 0.1 M Pb(NO3)2 solution at 20°C and contained a mixture of α-PbO2 and β-PbO2 phases. An electrochemical cell was used to follow phase transformations of the electrode in-situ under controlled potential conditions in 1 M H2SO4 at 20°C. Reduction to PbSO4 and reoxidation to PbO2 could be followed over a number (<50) of such redox cycles. Under the experimental conditions, the PbO2 deposit showed a relatively high degree of reversibility to PbSO4. The α-PbO2 phase was systematically transformed to β-PbO2.

S. E. Doyle

Papers

In situ studies of a dispersed platinum on carbon electrode using X-ray absorption spectroscopy

Instrumentation and cell design for in situ studies of electrode surfaces using x‐ray synchrotron radiation

Instrumentation and data acquisition for in situ electrochemistry at the Daresbury SRS

Integrated materials science facility on the SRS

In-situ X-ray diffraction studies of lead dioxide in sulphuric acid during potential cycling