Promotion of Proton Conduction in Polymer Electrolyte Membranes by 1H-1,2,3-Triazole

Abstract

We report 1H-1,2,3-triazole as an active group to dramatically enhance proton conduction in a polymer electrolyte membrane (PEM). The conductivities of a poly(4-vinyl-1H-1,2,3-triazole) membrane without any acidic dopants are about 105 times greater than those of poly(4-vinylimidazole) in dry air at 50-150 degrees C. Polymers with groups promoting proton conduction attached to the backbone have great potential to offer excellent mechanical properties and long-term stability. Further, 1H-1,2,3-triazole and PEMs containing 1H-1,2,3-triazole are stable in a wide potential range, implying excellent electrochemical stability under fuel cell operating conditions.

Novel polyelectrolytes containing perfluorocyclobutane and triazole units: synthesis, characterization and properties

“…The composition and structure of 6 were confirmed by Fourier transform infrared (FT-IR), 1 H-, 13 C-and 19 F-NMR. Compound 6b is discussed as a typical example.…”

“…Infrared spectra (IR) were obtained on a Thermo Electron Nicolet Avatar 360 FT-IR spectrometer (Thermo Fisher Scientific Inc., Waltham, MA, USA). 1 H nuclear magnetic resonance (NMR; 400 MHz), 13 C NMR (100MHz) and 19 F NMR (376 MHz) spectra were recorded on a Bruker Ultrashield 400 spectrometer (Bruker BioSpin AG, Fällanden, Switzerland). The relative molecular weights and distributions were measured with a Viscotek VE2001 GPC max system (Malvern Instruments, Worcestershire, UK).…”

“…indicated the two protons adjacent to the triazole ring. In the 13 C NMR spectrum of 6b (Figure 2), the typical signals of -OCF¼CF 2 groups were detected. The signals between 134.0 and 135.5 p.p.m.…”

“…Recently, nitrogencontaining heterocyclic compounds, such as imidazole, pyrazole and benzimidazole, have been suggested as proton solvents for proton exchange membrane fuel cells, and they may also be covalently tethered to some suitable polymers to prepare fully polymeric materials. [9][10][11][12][13][14][15][16][17][18] Liu et al 19 suggested that 1H-1,2,3-triazole has adequate electrochemical stability for fuel cell applications, and the 1H-1,2,3-triazole groups immobilized on a polymer backbone may open up new avenues in the design of polyelectrolytes. To date, several polymeric systems with tethered 1H-1,2,3-triazole moieties have been evaluated as polyelectrolytes.…”

“…To date, several polymeric systems with tethered 1H-1,2,3-triazole moieties have been evaluated as polyelectrolytes. [13][14][15][16][17] However, most of these polymers derived from polyacrylate or polyethylene may have issues related to their electrochemical or dimensional stability for medium temperature fuel cells. During the past decade, partially fluorinated polymers containing perfluorocyclobutane (PFCB) rings have been developed.…”