%0 Journal Article
%A Hou, Hui
%A Mariani, Alessandro
%A Suo, Yanpeng
%A Gao, Xinpei
%A Giffin, Jürgen
%A Rodenbücher, Christian
%A Passerini, Stefano
%A Korte, Carsten
%T Tuning Polybenzimidazole Membrane by Immobilizing a Novel Ionic Liquid with Superior Oxygen Reduction Reaction Kinetics
%J Chemistry of materials
%V 34
%N 10
%@ 0897-4756
%C Washington, DC
%I American Chemical Society
%M FZJ-2022-02099
%P acs.chemmater.1c03819
%D 2022
%X Protic ionic liquid (PIL) is a promising nonaqueous electrolyte alternative to replacing phosphoric acid for fuel cells operating at temperatures above 100 °C. In this study, the physical and electrochemical properties of stoichiometric and nonstoichiometric PILs are investigated focusing on their acid/base ratio. The study involves a series of PILs, generically indicated as N,N-diethyl-3-sulfopropane-1-ammonium trifluoromethanesulfonate ([DESPA+][TfO–]), varying from an excess of the proton acceptor (N,N-diethyl-3-aminopropane-1-sulfonic acid) to an excess of the proton donor (trifluoromethanesulfonic acid, TfOH). Compared to a state-of-the-art electrolyte, i.e., concentrated phosphoric acid, the nonstoichiometric [DESPA+][TfO–] shows superior oxygen reduction reaction kinetics on the investigated Pt catalysts and oxygen permeation ability (DO2·cO2). [DESPA+][TfO–] with a base-to-acid molar ratio of 1:2 achieves a current density ∼10 times larger than that of concentrated phosphoric acid at 110 °C and 0.8 V. Membranes including polybenzimidazole as a host polymer and stoichiometric and nonstoichiometric [DESPA+][TfO–] as the conductive electrolyte exhibit promising properties in terms of thermal stability and conductivity. At 120 °C and 40% relative humidity, conductivities of 2 and 16 mS cm–1 are achieved by the membranes employing stoichiometric and excess acid [DESPA+][TfO–], respectively.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000805874800005
%R 10.1021/acs.chemmater.1c03819
%U https://juser.fz-juelich.de/record/907595