New Types of Brönsted Acid–Base Ionic Liquids‐Based Membranes for Applications in PEMFCs

Abstract

A series of ionic liquids (ILs) are prepared by neutralizing tertiary amines with N,N‐bis(trifluoromethanesulfonyl)imide (HTFSI). As demonstrated by thermal and electrochemical characterizations, these ILs have very good temperature stability and a high ionic conductivity, that is, of the order of 10−2 S cm−1. By incorporating these ILs into a poly(vinylidenfluoride‐co‐hexafluoropropylene) polymer matrix, membranes with a high melting temperature, high decomposition point and with an ionic conductivity of about 10−2 S cm−1 at 140 °C, are obtained. These IL‐based, proton‐conducting membranes are proposed as new polymer electrolytes for high‐temperature polymer electrolyte membrane fuel cells (PEMFCs).

Conformational evolution of TFSI− in protic and aprotic ionic liquids

“…These ILs are promising candidates for the formation of IL-based proton conducting membranes. [32,33] By analyzing ILs of different cations, both protic and aprotic, we aim to better understand the influence of the molecular structure on the [C 1 ]/[C 2 ] conformational equilibrium. We analyze two different spectral ranges: the low wavenumber range 240-380 cm −1 and the wavenumber region of the intense Raman band at ∼740 cm −1 .…”

Thermodynamic study of POSS-based ionic liquids with various numbers of ion pairs

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] The increase in molecular weight and the presence of charges often cause an increase in the melting temperature. We have recently reported a polyhedral oligomeric silsesquioxane (POSS)-based room temperature IL that displays a melting temperature below 25 1C.…”

Conversion of Mono‐ and Disaccharides to Ethyl Levulinate and Ethyl Pyranoside with Sulfonic Acid‐Functionalized Ionic Liquids

“…In all these reactions ethyl levulinate was found to be the predominant product and yields of 68, 70 and 74 % were obtained with the ionic liquids [BMIm-SO 3 [NTf 2 ] gave a higher yield of ethyl levulinate (77 %) implying that the formation of ethyl levulinate followed the order of the acid strength of the ionic liquid. [23] The study was further extended to the sugars glucose and sucrose, and the results are presented in Table 2. All of the examined SO 3 H-ILs yielded 40 to 43 % of ethyl levulinate from sucrose with 97 % conversion.…”