TY - JOUR

T1 - Operando SAXS study of a Pt/C fuel cell catalyst with an X-ray laboratory source

AU - Schröder, Johanna

AU - Quinson, Jonathan

AU - Kirkensgaard, Jacob J.K.

AU - Arenz, Matthias

N1 - Publisher Copyright: © 2021 IOP Publishing Ltd.

PY - 2021

Y1 - 2021

N2 - Small-angle X-ray scattering (SAXS) is a powerful technique to investigate the degradation of catalyst materials. Ideally such investigations are performed operando, i.e. during a catalytic reaction. An example of operando measurements is to observe the degradation of fuel cell catalysts during an accelerated stress test (AST). Fuel cell catalysts consist of Pt or Pt alloy nanoparticles (NPs) supported on a high surface area carbon. A key challenge of operando SAXS measurements is a proper background subtraction of the carbon support to extract the information of the size distribution of the Pt NPs as a function of the AST treatment. Typically, such operando studies require the use of synchrotron facilities. The background measurement can then be performed by anomalous SAXS or in a grazing incidence configuration. In this work we present a proof-of-concept study demonstrating the use of a laboratory X-ray diffractometer for operando SAXS. Data acquisition of operando SAXS with a laboratory X-ray diffractometer is desirable due to the general challenging and limited accessibility of synchrotron facilities. They become even more crucial under the ongoing and foreseen restrictions related to the COVID-19 pandemic. Although, it is not the aim to completely replace synchrotron-based studies, it is shown that the background subtraction can be achieved by a simple experimental consideration in the setup that can ultimately facilitate operando SAXS measurements at a synchrotron facility.

AB - Small-angle X-ray scattering (SAXS) is a powerful technique to investigate the degradation of catalyst materials. Ideally such investigations are performed operando, i.e. during a catalytic reaction. An example of operando measurements is to observe the degradation of fuel cell catalysts during an accelerated stress test (AST). Fuel cell catalysts consist of Pt or Pt alloy nanoparticles (NPs) supported on a high surface area carbon. A key challenge of operando SAXS measurements is a proper background subtraction of the carbon support to extract the information of the size distribution of the Pt NPs as a function of the AST treatment. Typically, such operando studies require the use of synchrotron facilities. The background measurement can then be performed by anomalous SAXS or in a grazing incidence configuration. In this work we present a proof-of-concept study demonstrating the use of a laboratory X-ray diffractometer for operando SAXS. Data acquisition of operando SAXS with a laboratory X-ray diffractometer is desirable due to the general challenging and limited accessibility of synchrotron facilities. They become even more crucial under the ongoing and foreseen restrictions related to the COVID-19 pandemic. Although, it is not the aim to completely replace synchrotron-based studies, it is shown that the background subtraction can be achieved by a simple experimental consideration in the setup that can ultimately facilitate operando SAXS measurements at a synchrotron facility.

KW - degradation

KW - fuel cell catalyst

KW - Operando spectroscopy

KW - small-angle X-ray scattering

U2 - 10.1088/1361-6463/abfa39

DO - 10.1088/1361-6463/abfa39

M3 - Journal article

VL - 54

JO - Journal Physics D: Applied Physics

JF - Journal Physics D: Applied Physics

SN - 0022-3727

IS - 29

M1 - 294004

ER -