Electrochemical quartz crystal microbalance study of high-rate Pt dissolution in H2O2-containing H2SO4 solution with Fe2+ ion

Abstract Pt dissolution in an H 2 SO 4 solution was investigated in the presence of both H 2 O 2 and Fe 2+ using an electrochemical quartz crystal microbalance (EQCM). The EQCM data in the H 2 O 2 -containing H 2 SO 4 with and without Fe 2+ showed that a remarkable Pt dissolution occurred during the cathodic potential step of 1.36 → 0.36 V vs. RHE from the 4th cycle, which is further enhanced by the presence of Fe 2+ . The mass gains and mass losses observed up to the 3rd cycle were also more significant in the presence of Fe 2+ , suggesting that the roughness of the Pt electrode surface remarkably increased. This phenomenon may be caused by the enhanced O 2 generation due to the significant decomposition of H 2 O 2 . As a result, Pt oxidants inducing the cathodic Pt dissolution significantly form from the rearranged Pt atoms, which contribute to the high-rate Pt dissolution in the presence of both H 2 O 2 and Fe 2+ .