Center for Electrochemistry, Department of Chemistry, The University of Texas at Austin , Austin, Texas 78712, United States.
J Am Chem Soc. 2015 Nov 4;137(43):13752-5. doi: 10.1021/jacs.5b08628. Epub 2015 Oct 21.
We report the electrodeposition of electrocatalytic clusters of platinum from femtomolar platinate solutions. An inert carbon fiber ultramicroelectrode (UME) was held at a potential where proton reduction was unfavorable on carbon but favorable on platinum in a 1 M sulfuric acid solution. Upon addition of femtomolar amounts of hexachloroplatinic acid, which will also reduce to Pt(0) at the applied potential on the carbon fiber UME, cathodic blips were observed in the amperometric i-t response. These blips correspond to the reduction of protons to molecular hydrogen at the small platinum clusters followed by a rapid deactivation likely due to hydrogen bubble formation. On average, these current spikes occur when five platinum atoms have been formed on the electrode, as determined by a comparative analysis of experimental cathodic blips and calculated hexachloroplatinate molecule collision frequencies.
我们报告了从毫微微摩尔的高氯酸盐溶液中电沉积电催化铂簇的情况。在 1 M 硫酸溶液中，将惰性碳纤维超微电极 (UME) 保持在一个电位，在该电位下，质子还原在碳上是不利的，但在铂上是有利的。加入毫微微摩尔量的六氯合铂酸，在碳纤维 UME 上施加的电势下也会还原为 Pt(0)，在安培电流响应中观察到阴极跃变。这些跃变对应于在小的铂簇上质子还原为氢气，随后由于氢气泡形成而迅速失活。平均而言，当电极上形成五个铂原子时，会发生这些电流尖峰，这是通过比较实验阴极跃变和计算的六氯合铂酸分子碰撞频率确定的。
