Preparation of a “green” composite based on imidazole and nanocrystalline cellulose for fuel cell application

Abstract

In this work, we have successfully synthesized cellulose nanocrystals-Imidazole (CNC/Im) composite, capable of proton conductivity under low humidity conditions for applications in the fuel cell field. The composition, structure, and morphology of prepared CNC/Im material were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscope (SEM). The thermal properties and proton conductivity of CNC/Im were determined and compared with that of pure cellulose nanocrystals. electrochemical impedance spectroscopy (EIS) analysis showed that the obtained proton conductivity of CNC/Im under a relative humidity of 40% at 30oC was significantly improved, six times higher than that of pure CNC. This value depends on the n index (the linked Im in the molar ratio to glucose units). In this study, the n index was determined based on the equation from the analysis of the differential scanning calorimetry (DSC) diagrams and got the value of n equal to 1:17. In addition, thermogravimetric analysis (TGA) results also indicated that CNC/Im composite material has higher thermal stability than CNC. This CNC/Im composite will be a promising candidate for solid proton conductive membrane in fuel cell operating in low humidity conditions.