Synthesis of New Protic Ionic Liquids for Fuel Cells on the Basis of In-Situ FT-IR Measurements

摘要

A series of protic ionic liquids (ILs) were synthesized from N,Ndiethylmethylamine (dema) and three kinds of imides having different fluoroalkyl chain lengths (H-N(SO_2(CF_2)_nF)_2, n = 0-2) as electrolytes for fuel cells. The effect of anion structure on the oxygen reduction reaction (ORR) activity of Pt electrode was investigated in detail using the prepared ILs. As increasing n of imide-anion, the ORR current was increased. The onset potential for ORR was also shifted towards the positive side as extending the fluoroalkyl chain of imide-anion. This potential shift was clearly revealed by in-situ FT-IR measurement to relate the anion adsorbability on the Pt electrode, depending on the fluoroalkyl chain length of imide structure.