Investigation of the influence of amino trimethylene phosphonic acid on oxygen reduction reaction on platinum catalyst

Recently, organic phosphonic acids (OPAs)/PA were developed as an excellent dual-proton conductor in high-temperature polymer electrolyte membrane fuel cells to solve the leaching of PA. However, the effect of OPAs on the catalytic property of Pt is still unclear. In this work, we investigate the influence of amino trimethylene phosphonic acid (ATMP) on oxygen reduction reaction (ORR) on Pt catalyst through a combined experimental and simulation study. It is found ATMP caused a 15 mV negative shift in half-wave potential which is only half of PA and a 60 % increase in mass activity compared to PA, indicating its weaker poisoning effect. The reason is that the N-containing structures of ATMP molecules could benefit the catalytic property of Pt for its regulation to the electronic structure of Pt. Meanwhile, Pt shows higher durability in ATMP than PA due to the weaker adsorption of ATMP on Pt surface. Therefore, the role of ATMP should be utilized for designing ORR catalyst in high-temperature polymer electrolyte membrane fuel cells.