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Ion-exchange-induced selective etching for the synthesis of amino-functionalized hollow mesoporous silica for elevated-high-temperature fuel cells

journal contribution
posted on 20.09.2017, 00:00 authored by Jin Zhang, Jian Liu, Shanfu Lu, Haijin Zhu, David Aili, Roland De Marco, Yan Xiang, Maria ForsythMaria Forsyth, Qingfeng Li, San Ping Jiang
As differentiated from conventional synthetic processes, amino-functionalized hollow mesoporous silica (NH2-HMS) has been synthesized using a new and facile strategy of ion-exchange-induced selective etching of amino-functionalized mesoporous silica (NH2-meso-silica) by an alkaline solution. Nuclear magnetic resonance (NMR) spectroscopy and in situ time-resolved small-angle X-ray scattering (SAXS) reveal that ion-exchange-induced selective etching arises from the gradient distribution of OH- in the NH2-meso-silica nanospheres. Moreover, the ion-exchange-induced selective etching mechanism is verified through a successful synthesis of hollow mesoporous silica. After infiltration with phosphotungstic acid (PWA), PWA-NH2-HMS nanoparticles are dispersed in the poly(ether sulfone)-polyvinylpyrrolidone (PES-PVP) matrix, forming a hybrid PWA-NH2-HMS/PES-PVP nanocomposite membrane. The resultant nanocomposite membrane with an optimum loading of 10 wt % of PWA-NH2-HMS showed an enhanced proton conductivity of 0.175 S cm-1 and peak power density of 420 mW cm-2 at 180 °C under anhydrous conditions. Excellent durability of the hybrid composite membrane fuel cell has been demonstrated at 200 °C. The results of this study demonstrated the potential of the facile synthetic strategy in the fabrication of NH2-HMS with controlled mesoporous structure for application in nanocomposite membranes as a technology platform for elevated-temperature proton exchange membrane fuel cells.

History

Journal

ACS applied materials and interfaces

Volume

9

Issue

37

Pagination

31922 - 31930

Publisher

ACS Publications

Location

Washington, D.C.

eISSN

1944-8252

Language

eng

Publication classification

C1 Refereed article in a scholarly journal

Copyright notice

2017, American Chemical Society