Centre d’Élaboration de Matériaux et d’Etudes Structurales (UPR 8011)


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Improved oxygen reduction reaction in fuel cell through carbon interphase

par Cemes23 - publié le

We propose a modified hybrid support consisting of unzipped carbon nanotubes and nitrogen and sulfur co-doped multi walled carbon nanotubes as high performance electrocatalyst for the oxygen reduction reaction in proton exchange membrane fuel cells. Raman and TEM investigations showed that improved and stronger interaction between the Pt nanoparticles and the support material increases performance and durability at high power density of 642 mW/cm2. Reduced graphene oxide is found to not improve the cell performance.

 

Proton exchange membrane fuel cells (PEMFC) are promising green technology alternatives. The high cost resulting from the use of Pt-based electrocatalysts and stability issues are bottlenecks in commercialization of PEMFC. Oxygen reduction reaction (ORR) reaction kinetics is much slower than the hydrogen oxidation reaction (HOR) occurring at the anode, which implies high amount of catalyst loading at the cathode side. Efforts are being made to reduce Pt loading either by alloying or by appropriately tailoring and doping the support material. Using a support material with high degree of graphitization like carbon nanotubes/graphene composite materials have the advantage to present a good thermal stability and electrochemically conductivity and to be electrochemically stable. We reported, a hybrid 1D-2D carbonaceous material comprising multiwall carbon nanotubes (MWCNTs) and few-layer graphene (FLG) as support for Pt catalyst in PEMFCs, where graphene is expected to compensate for the relatively low electrochemical surface area of MWCNTs. Our results show using Raman spectroscopy, transmission electron microscopy (STEM-EDS) and XPS that a strong interfacial bonding between the catalyst particle and the support is crucial to prevent degradation of the catalyst material using. We demonstrate that the in-situformed co-doped 1D-2D support leads to a higher performance when compared to similar hybrid supports obtained by adding reduced graphene oxide (rGO) to co-doped CNTs.

JPEG - 22.4 ko
Schéma de nanotubes de carbone exfoliés dopés à l’azote et au soufre avec et sans oxyde de graphène réduit

We have used a modified hybrid support consisting of unzipped carbon nanotubes and N and S co-doped MWCNTs to develop a high performance electrocatalyst for the ORR in PEMFC. By comparing four different supports, we found that a strong interaction between the catalyst nanoparticles and the support material is crucial for ORR activity so as to increase performance and durability of PEMFC. Fuel cell measurements show that Pt/NS PECNTleads to high power density of 642 mW/cm2, which is30% higher than that observed when combining with reduced graphene oxide. 

 

Acknowledgement

This work has been carried out within the CEFIPRA Indo-French project DUPONT (2017-2020)

Reference 

Optimizing metal-support interphase for efficient fuel cell oxygen reduction reaction catalyst

Divya Nechiyil, Meenakshi Seshadhri Garapati, Rashmi Chandrabhan Shende, Sébastien Joulié, David Neumeyer, Revathi Bacsa, Pascal Puech, Sundara Ramaprabhu, Wolfgang Bacsa

Journal of Colloid and Interface Science 561 (2020) 439-448, doi.org/10.1016/j.jcis.2019.11.015

Contact

W. Bacsa, P. Puech