Superacidity in Nafion/MOF Hybrid Membranes Retains Water at Low Humidity to Enhance Proton Conduction for Fuel Cells

Abstract

A hybrid membrane of superacid sulfated Zr-MOF (SZM) and Nafion shows much superior performance to Nafion, particularly for fuel cell operating under low humidity. The Brønsted acidic sites in SZM networks retain an ample amount of water which facilitated proton conduction under low humidity. The water retention properties of Nafion-SZM hybrid membranes with 1 wt % loading of SZM increased at 35% relative humidity and outperformed commercial unfilled Nafion membrane. The proton conductivity increases by 23% for Nafion-SZM hybrid compared to unfilled Nafion membrane. The Nafion-SZM membrane also shows higher performance stability at 35% relative humidity than Nafion, as confirmed by close monitoring of the change of open circuit voltage for 24 h.

Preparation of Covalent-Ionically Cross-Linked UiO-66-NH2/Sulfonated Aromatic Composite Proton Exchange Membranes With Excellent Performance

“…However, their proton conduction channels are not consecutive enough and the fabrication of MOFs into the form of membranes is still immature, which restricts their proton conductivity and limits their practical application. The fabrication of MOFs into sulfonated polymer matrix is a significant step for their practical application (Patel et al, 2016;Dong et al, 2017). Sulfonated polymers are not only easy-to-prepare membranes, but also act as a good medium to form continuous and effective channels for proton conduction.…”

Improving the performance of sulfonated polymer membrane by using sulfonic acid functionalized hetero‐metallic metal‐organic framework for DMFC applications

“…Patel and coworkers studied the effect of sulfated Zr‐MOF‐808 (SZM) on Nafion membranes. The Nafion/SZM hybrid exhibited 23% increased ionic conductivity over the unfilled Nafion membranes at 35% relative humidity (RH) . Wu's group reported the effect of co‐doping of two different MOF (UiO‐66‐NH 2 and UiO‐66‐SO 3 H) in Nafion membranes.…”

“…The Nafion/SZM hybrid exhibited 23% increased ionic conductivity over the unfilled Nafion membranes at 35% relative humidity (RH). 29 Wu's group reported the effect of co-doping of two different MOF (UiO-66-NH 2 and UiO-66-SO 3 H) in Nafion membranes. They found that the co-doping of the two different MOFs in Nafion caused more continuous hydration channels that greatly enhanced the proton conductivity.…”

CNT/SPEEK Nano‐Composite Membranes: Toward Improved Properties

“…Various membranes have been prepared incorporating filler material e.g. metal organic framework, graphene, silica nanoparticles etc for enhancing membrane performance . In recent year many researchers are focusing on carbon nanotubes due to its impressive optical, electrical, thermal and mechanical properties that make them amenable to a range of applications including water purification, catalysis, hydrogen storage, fuel cell etc .…”

“…metal organic framework, graphene, silica nanoparticles etc for enhancing membrane performance. [12][13][14][15][16] In recent year many researchers are focusing on carbon nanotubes due to its impressive optical, electrical, thermal and mechanical properties that make them amenable to a range of applications including water purification, catalysis, hydrogen storage, fuel cell etc. [17][18][19][20] Membranes based on CNTs have remarkable properties such as high flux, high selectivity and low fouling which makes them useful for NF process.…”