Spatial imaging of catalyst poisoning with SO₂ on Pt/C PEFC electrocatalyst by operando Pt L_III-edge XAFS-CT imaging

Abstract

Sulfur dioxide (SO2), which is one of air contaminants, causes drastic power loss of Pt electrocatalysts in polymer electrolyte fuel cells (PEFCs). Herein, we report the spatial imaging of catalyst...

Three-Dimensional Visualization of Adsorption Distribution in a Single Crystalline Particle of a Metal–Organic Framework

“…The combination of XCT and X-ray absorption fine structure (XAFS) spectroscopy, which is called XAFS-CT, has been developed recently. By integrating the 3D images of a material with information on its local chemical state, it is now possible to elucidate the reaction mechanisms of practical materials; for example, the degradation of Pt-alloy electrocatalysts in a working polymer electrolyte fuel cell, − oxygen storage in a three-way automobile catalyst, , and heterogeneous rubber/brass composites …”

In situ 3D X-ray imaging of water distribution in each layer of a membrane electrode assembly of a polymer electrolyte fuel cell

“…X-ray radiography/computed tomography (CT) techniques have been successfully applied to the 2D/3D imaging of liquid water in PEFCs. 24–26 Previous expertized works revealed the different distribution of liquid water to the support materials of catalyst layers, 27 the growth of liquid water droplets and the removal of water plugs in the fluid channel of operating PEFC, 28 the requirement of a microporous layer to decrease the liquid water at the interface of MEA CL and GDL, and so forth. 29 In addition, high-speed 4D neutron CT allowed quantitative analysis of the water distribution in a PEFC during operation, albeit with limited spatial resolution (the MEA and GDLs were observed as a single layer).…”

“…S2, ESI†). 25 To calculate 3D images of the water in the PEFC, we first performed measurements in the absence of conspicuous water accumulation (dry conditions: N 2 flow with a relative humidity (RH) of 64%) and recorded the CT data. Next, the PEFC was operated under wet conditions at 0.4 V. After the cell current had been steady for at least 15 min, both the inlet and outlet gas valves of the PEFC were closed to quench the reactions inside the MEA.…”