The particle proximity effect: from model to high surface area fuel cell catalysts

RSC Advances ◽  
2014 ◽  
Vol 4 (29) ◽  
pp. 14971 ◽  
Author(s):  
Jozsef Speder ◽  
Lena Altmann ◽  
Marcus Bäumer ◽  
Jacob J. K. Kirkensgaard ◽  
Kell Mortensen ◽  
...  
2018 ◽  
Vol 11 (4) ◽  
pp. 988-994 ◽  
Author(s):  
Masanori Inaba ◽  
Anders Westergaard Jensen ◽  
Gustav Wilhelm Sievers ◽  
María Escudero-Escribano ◽  
Alessandro Zana ◽  
...  

In this work, we introduce the application of gas diffusion electrodes (GDE) for benchmarking the electrocatalytic performance of high surface area fuel cell catalysts.


2021 ◽  
Author(s):  
Johanna Schröder ◽  
Jonathan Quinson ◽  
Jacob J. K. Kirkensgaard ◽  
Matthias Arenz

Small angle X-ray scattering (SAXS) is a powerful technique to investigate the degradation of catalyst materials. Ideally such investigations are performed <i>operando</i>, i.e., during a catalytic reaction. An example of <i>operando </i>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 (aSAXS) or in a grazing incidence con-figuration. In this work we present a proof-of-concept study demonstrating the use of a laboratory X-ray diffractometer for <i>operando </i>SAXS. Data acquisition of <i>operando </i>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 <i>operando </i>SAXS measurements at a synchrotron facility. <br>


Author(s):  
Bhupesh Chandra ◽  
Joshua T. Kace ◽  
Yuhao Sun ◽  
S. C. Barton ◽  
James Hone

In recent years carbon nanotubes have emerged as excellent materials for applications in which high surface area is required e.g. gas sensing, hydrogen storage, solar cells etc. Ultra-high surface to volume ratio is also a desirable property in the applications requiring enhanced catalytic activity where these high surface area materials can act as catalyst supports. One of the fastest developing areas needing such materials is fuel-cell. Here we investigate the process through which carbon nanotubes can be manufactured specifically to be used to increase the surface area of a carbon paper (Toray™). This carbon support is used in bio-catalytic fuel cell as an electrode to support enzyme which catalyzes the redox reaction. Deposition of nanotubes on these carbon fibers can result in great enhancement in the overall surface area to support the enzyme, which increases the reaction rate inside the fuel cell. The present paper describes a method to achieve ultra-thick growth of multiwall carbon nanotubes (MWNT) on a carbon Toray™ paper using a joule heating process and gas-phase catalyst. Using this method, we are able to achieve rapid, high-density, and uniform MWNT growth. This method is also potentially scalable toward larger-scale production.


2011 ◽  
Vol 158 (10) ◽  
pp. B1255 ◽  
Author(s):  
K. J. Blackmore ◽  
L. Elbaz ◽  
E. Bauer ◽  
E. L. Brosha ◽  
K. More ◽  
...  

2021 ◽  
Author(s):  
Johanna Schröder ◽  
Jonathan Quinson ◽  
Jacob J. K. Kirkensgaard ◽  
Matthias Arenz

Small angle X-ray scattering (SAXS) is a powerful technique to investigate the degradation of catalyst materials. Ideally such investigations are performed <i>operando</i>, i.e., during a catalytic reaction. An example of <i>operando </i>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 (aSAXS) or in a grazing incidence con-figuration. In this work we present a proof-of-concept study demonstrating the use of a laboratory X-ray diffractometer for <i>operando </i>SAXS. Data acquisition of <i>operando </i>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 <i>operando </i>SAXS measurements at a synchrotron facility. <br>


2018 ◽  
Author(s):  
Norbert Radacsi ◽  
Fernando Diaz Campos ◽  
Calum Chisholm ◽  
Konstantinos P. Giapis

Nanofibers spontaneously decorated with nanoparticles were synthesized by nozzle-free electrospinning, showcasing the latter as a novel, inexpensive and scalable method for depositing high-surface area composites. Layers of nanofibers of the intermediate-temperature proton conducting electrolyte cesium dihydrogen phosphate, (CsH2PO4, CDP), were deposited from homogeneous undersaturated solutions of CDP and polyvinylpyrrolidone (PVP), uniformly over large area substrates. Under certain conditions, the nanofibers develop CDP nanoparticles on their surface, which increases the exposed electrolyte surface area and ultimately enhances electrocatalytic performance. Indeed, fuel cell tests on cathodes made of processed nanoparticle-decorated CDP nanofibers produced higher cell voltage, as compared to state-of-the-art electrodes.


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