The HER in alkaline media on Pt-modified three-dimensional Ni cathodes

详细信息    查看全文

• 作者：Stefania Fiameni ; Isaac Herraiz-Cardona ; Marco Musiani ; Valent¨ªn P¨¦rez-Herranz ; Lourdes V¨¢zquez-G¨®mez ; Enrico Verlato
• 关键词：Electrocatalysis ; Foam electrodes ; Galvanic displacement ; HER ; Porous electrodes ; Spontaneous deposition
• 刊名：International Journal of Hydrogen Energy
• 出版年：2012
• 出版时间：July, 2012
• 年：2012
• 卷：37
• 期：14
• 页码：10507-10516
• 全文大小：1383 K

文摘

Electrodeposited porous Ni layers and commercial Ni foams were submitted to spontaneous deposition of Pt, achieved by immersing the Ni substrates in H₂PtCl₆ solutions, at open circuit, to produce Pt-modified 3D Ni electrodes. When using Ni foams, the immersion was prolonged until the whole amount of H₂PtCl₆ in the solution had reacted. Such an approach, which granted an easy control of the Pt loading, could not be used for Ni electrodeposits, since they underwent significant corrosion. The true Pt surface area was determined by measuring, for each electrode, the hydrogen desorption charge according to methods described in the literature. The ratios between Pt surface area and Pt loading were higher for Ni foam electrodes than for porous Ni electrodeposits. Both kinds of Pt-modified Ni electrodes were used as cathodes for hydrogen evolution in 1?M KOH. Cathodes with Pt loading below 0.5?mg?cm^?2 (referred to geometric surface area) evolved hydrogen at ?100?mA?cm^?2 with a ?75?mV overpotential. The better activity of foam electrodes as compared to electrodeposits, especially at low Pt loading, was mainly due to their higher Pt surface area per unit Pt mass.