铅铋合金在H_2SO_4溶液中的析氢反应

Hydrogen e volution reaction on Pb-Bi alloy in H_2S O_4

采用线性电位扫描法、气体收集实验以及电化学阻抗法研究了纯铅电极和铅铋(0.05%Bi)合金电极在硫酸溶液中的析氢反应。阴极极化曲线测量表明,相同电位下,纯铅电极上的析氢电流大于铅铋合金电极上的析氢电流;氢气收集实验表明,相同电位下,纯铅电极上收集到的氢气的体积大于铅铋合金电极;交流阻抗实验表明,在两种电极上的析氢反应均受电荷传递控制,相同电位下,纯铅上的析氢反应电阻小于铅铋合金电极上的反应电阻。铅铋合金中铋的存在对析氢反应起抑制作用,且电位越负,铋的抑制作用越明显。

Hydrogen evoluti on reactions on pure Pb and Pb-Bi (0.05% Bi) alloy were studied by the liner swe ep voltammetry, the measurement of the v olume of hydrogen evolution and the alte rnative curr ent impedance. The results show that the reaction current of hydrogen evolution on Pb is higher than that on Pb-Bi alloy at the same potentials in the cathodic polarization curves. The volume of hydro gen evolution on Pb is larger than that on Pb-Bi alloy at the same cathodic pote ntials. The hydrogen evolution reactions on both Pb and Pb-Bi alloys are cont rolled by charge transfer step. The reac tion resistance for hydrogen evolution o btained from the Nyquist plot on Pb is s maller than that on Pb-Bi alloy at the s ame cathodic potentials. Bi in Pb-Bi all oy plays a role that suppresses hydrogen evolution and the suppression effect of Bi strengthens as the potential becomes more negative.