Metal tri-phosphonates containing aliphatic tertiary amines for medium-temperature proton conduction. (29th July 2022) - Xia, Zihan
Abstract: New medium-temperature proton conductors (MATMP) were synthesized from amino trimethylene phosphonic acid (ATMP) and metal ions (Fe 2+, Ce 4+ and Zr 4+ ) with varying molar ratios. The high content of phosphonic acid groups of ATMP endowed MATMP with good ion exchange capacity (IEC, 0.58∼3.45 meq·g −1 ) and proton conductivity. The aliphatic tertiary amine in ATMP improved proton conduction via ionic and hydrogen bonds. The proton conductivity of FeATMP(1:2) reached 0.124, 0.079 and 0.038 S cm −1 at 100%, 50% and 0 RH at 180 °C, respectively. MATMP exhibited good thermal and oxidative stability, demonstrating promising applications in fuel cell technology. Highlights: Metal tri-phosphonates containing aliphatic tertiary amine (MATMP) is synthesized. MATMP was insoluble in water with good thermal stability and oxidative stability. Abundant phosphonic acid and amine groups form intensive ionic and hydrogen bonds. The ion exchange capacity and proton conductivity are good at medium temperature.