Nafion/SiO₂@TiO₂‐palygorskite membranes with improved proton conductivity

Abstract

This work deals with the synthesis of SiO2@TiO2 supported palygorskite fibers and their use as a filler for proton exchange membrane fuel cells in order to improve their performance. SiO2@TiO2‐palygorskite nanostructured particles were synthesized separately with original route to ensure the growth of TiO2 and then of SiO2 on the surface of the clay. Accordingly, the introduction of the synthetic filler (SiO2@TiO2‐paly) into the electrolyte membrane (Nafion) aims to improve mechanical, thermal, and proton conductivity properties. The TiO2 nanoparticles were generated via a sol–gel process on the external surface of palygorskite. Then, SiO2 nanoparticles were synthetized using a similar sol–gel process, onto the TiO2‐palygorskite particles to produce the final SiO2@TiO2‐palygorskite particles. The physico‐chemical properties of the nanostructured particles were studied by X‐ray diffractometry, Fourier transform infrared, scanning electron microscopy, and transmission electron microscopy. Nafion based composite membranes were prepared using SiO2@TiO2‐palygorskite and TiO2‐palygorskite as a control standard. The composite membranes show improved mechanical properties, thermal stability, water retention, and proton conductivity compared to the neat Nafion membrane. Proton conductivities (at 100°C and 100% relative humidity) increased from 65.0 mS/cm for neat Nafion to 70.4 mS/cm and to 128.6 mS/cm when incorporated TiO2‐Paly (6% in weight) and SiO2@TiO2‐Paly (6% in weight), respectively.

Advancing High-Temperature PEMFCs: Synthesis and Characterization of Poly(2,5-benzimidazole) Nanoclay/SPVC Composite Membranes

“…The literature showed that the induction of inorganic fillers, including SiO 2 and TiO 2 , enhanced the acid retention capability. , Our findings are in agreement with previous studies. , It is important to remember that the unique chemical structure of imidazole was linked to its notable PA doping capability. Generally, doping a membrane with more PA molecules increases its proton conductivity because of the more dynamic hydrogen-bond networks; however, this comes at the membrane’s mechanical strength and swelling costs.…”

“…43 The literature showed that the induction of inorganic fillers, including SiO 2 and TiO 2 , enhanced the acid retention capability. 90,91 Our findings are in agreement with previous studies. 92,93 It is important to remember that the unique chemical structure of imidazole was linked to its notable PA doping capability.…”

Suppression of Membrane Degradation Accompanied with Increased Output Performance in Fuel Cells by Use of Silica-Containing Anode Catalyst Layers

“…The incorporation of radical scavengers/quenchers (i.e., CeO 2 , TiO 2 , ZrO 2 , MnO 2 , and other metal oxides) into the PEM or CLs has been effective in mitigating the decomposition rate of the PEM. − However, a serious drawback has been recognized in the use of radical scavengers based on redox reactions of transition-metal cations; i.e., the ion exchange of the metal cations such as Ce 3+ lowered the σ H of the electrolyte, both the membrane itself and the ionomer in the cathode CL, resulting in severe polarization loss. , Thus, it is of the utmost importance to escape the trade-off between the PEM durability and output performance that exists for the radical scavengers employed so far.…”

Hybrid 3D‐Ordered Membrane Electrode Assembly (MEA) with Highly Stable Structure, Enlarged Interface, and Ultralow Ir Loading by Doping Nano TiO2 Nanoparticles for Water Electrolyzer

“…TiO 2 nanoparticles are widely available due to their inexpensiveness and high mechanical strength, good electrochemical resistance, and thermal stability, [35][36][37] enabling them to maintain stability in high voltage and acidic environments characteristic of PEMWE. In this work, we choose TiO 2 as the filler.…”