Covalent organic framework–based porous ionomers for high-performance fuel cells

Covalent organic framework–based porous ionomers
for high-performance fuel cells
Qingnuan Zhang1
, Shuda Dong1
, Pengpeng Shao1
, Yuhao Zhu1
, Zhenjie Mu1
, Dafei Sheng1
,
Teng Zhang1
, Xin Jiang2
, Ruiwen Shao3
, Zhixin Ren1
, Jing Xie1
, Xiao Feng1
*, Bo Wang1
*
Lowering platinum (Pt) loadings without sacrificing power density and durability in fuel cells is highly
desired yet challenging because of the high mass transport resistance near the catalyst surfaces. We
tailored the three-phase microenvironment by optimizing the ionomer by incorporating ionic covalent
organic framework (COF) nanosheets into Nafion. The mesoporous apertures of 2.8 宛先 4.1 nanometers
and appendant sulfonate groups enabled the proton transfer and promoted oxygen permeation. The
mass activity of Pt and the peak power density of the fuel cell with Pt/Vulcan (0.07 mg of Pt per square
centimeter in the cathode) both reached 1.6 times those values without the COF. This strategy was
applied to catalyst layers with various Pt loadings and different commercial catalysts.

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