多孔Ni-Cu-Ti-La_(2)O_(3)复合电极的制备及其析氢性能

Preparation and hydrogen evolution performance of porous Ni-Cu-Ti-La_(2)O_(3) composite electrodes

采用粉末冶金方法烧结制备了多孔Ni-Cu-Ti-La_(2)O_(3)复合电极,讨论不同La_(2)O_(3)的掺杂量对电极析氢性能的影响。利用X射线衍射(XRD)、扫描电镜(SEM)、能谱仪(EDS)等测试手段对电极的微观结构和物相组成进行表征。结果表明:Ni-Cu-Ti合金体系中La_(2)O_(3)的掺杂可有效提高电极材料的电荷传输速率,多孔Ni-Cu-Ti-La_(2)O_(3)复合电极在6 mol/L KOH溶液中表现出良好的析氢催化活性,其整体析氢催化活性明显优于多孔Ni-Cu-Ti、Ni-Cu-W、Ni-Cu-Co、Ni-Cu-Zr和Ni-Cu电极;当烧结温度为1000℃时,成分为Ni-Cu-Ti-9La的多孔复合电极具有最佳的析氢催化性能,其Tafel斜率为63.18 mV/dec,电流密度在10 mA/cm^(2)时过电位为1077 mV(vs Hg/HgO),多孔Ni-Cu-Ti-La_(2)O_(3)复合电极催化活性的提高得益于d轨道左半金属元素La和右半金属元素Ni、Cu之间的协同作用和其真实表面积的增大。

The porous Ni-Cu-Ti-La_(2)O_(3) composite electrodes were prepared by powder metallurgy sintering.The effects of different doping amounts of La_(2)O_(3) on the hydrogen evolution performance of the electrodes were discussed.The phase composition and microstructure of the electrodes were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),and energy dispersive spectrometer(EDS).The results show that the doping of La_(2)O_(3) in the Ni-Cu-Ti alloy can effectively improve the charge transfer rate of the electrode material.The porous Ni-Cu-Ti-La_(2)O_(3) composite electrode has a good catalytic activity for hydrogen evolution reaction in 6 mol/L KOH solution,and its overall catalytic activity for hydrogen evolution is better than that of porous Ni-Cu-Ti,Ni-Cu-W,Ni-Cu-Co,Ni-Cu-Zr,and Ni-Cu electrodes.When the sintering temperature is 1000℃,the porous composite electrode with the composition of Ni-Cu-Ti-9La has the best catalytic performance for hydrogen evolution reaction.The Tafel slope is 63.18 mV/dec and the overpotential is 1077 mV(vs Hg/HgO)at the current density of 10 mA/cm^(2).The improvement of catalytic activity of the porous Ni-Cu-Ti-La_(2)O_(3) composite electrode is attributed to the synergistic effect between the left semimetal element La and the right semimetal element Ni and Cu of the d-orbital,as well as the increase of its real surface area.