Details

Autor(en) / Beteiligte

• Ressam, Ibtissam
• El Kadib, Abdelkrim
• Lahcini, Mohammed
• Luinstra, Gerrit A.
• Perrot, Hubert
• Sel, Ozlem

Titel

Enhanced proton transport properties of Nafion via functionalized halloysite nanotubes

Ist Teil von

• International journal of hydrogen energy, 2018-10, Vol.43 (40), p.18578-18591

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The introduction of naturally occurring fibrillary structured halloysite clays (HNTs) into the Nafion matrix resulted in an enhanced proton conductivity and a reduced activation energy for proton transport. To assess the effect of the various states of the HNTs as a membrane additive, the σH+ of the composite membranes (Nafion/HNTs, Nafion/HNTs-NH2, Nafion/HNTs-SO3H) was measured at 30 °C and 80 °C and at different levels of relative humidity (%RH). An overall improvement of the σH+ of the Nafion was observed in the presence of the nanotubular additives (HNTs or HNTs-NH2) which can be attributed to the high specific surface area accommodating hydrophilic functional groups and therefore contributing to the water retention/management in the composite membrane. However, the Nafion/HNT-SO3H composites are distinguished in terms of enhanced performance in σH+ which persist in the whole range of % RH levels and noted that the σH+ values are almost 2 times higher than native Nafion in the low humidity region (30%–50%) and at 80 °C. In agreement with the σH+ enhancement, the activation energy is lower than that of native Nafion indicating that the proton transport is facilitated in the presence of -SO3H modified HNTs, probably due to an improved connectivity and arrangement of ionic conducting domains. •Naturally occurring halloysites were functionalized with –NH2 and –SO3H groups.•The introduction of functionalized halloysite nanotubes enhances the σH+ of Nafion.•The σH+ values are 2 times higher than Nafion, also in the low humidity (30%–50%).•In line with the σH+ enhancement, the Ea is lower than that of pristine Nafion.