三元合金Au-Cu-Ni/C纳米粒子对BHˉ4电催化性能的影响

摘要

为抑制直接硼氢化物燃料电池中的 BH-4在阳极氧化反应中的水解问题,采用传统的多元醇还原法制备了 Au/C,Au1-Cu4/C 和 Au0.5-Cu1-Ni1/C 等3种纳米粒子,并对 BH-4在不同催化剂上的电氧化性能进行了测试.结果表明:所制备的3种纳米粒子均匀地分布在碳载体上,平均粒径约在8~17 nm 之间.BH-4在 Au0.5-Cu1-Ni1/C 上发生直接氧化的电位最负,氧化转移的电子数最多,为6.0,大约是 Au/C 纳米粒子转移电子数的6倍.在贵金属 Au 含量均为20%的两种纳米粒子Au1-Cu4/C 和Au0.5-Cu1-Ni1/C 上,Au0.5-Cu1-Ni1/C 有更小的电荷转移电阻331.9 Ω/cm2,3种纳米粒子的催化性能由大到小依次为:Au0.5-Cu1-Ni1/C,Au1-Cu4/C,Au/C.故在二元合金催化剂 Au-Cu/C 的基础上发展三元合金催化剂 Au-Cu-Ni/C 很有必要.%In order to restrain BH-4hydrolysis and promote BH-4oxidation in direct boro-hydride fuel cell,Au/C,Au1-Cu4/C and Au0.5-Cu1-Ni1/C nano-particles were synthesized by a conventional polyol reduction method.The results of the physical characterization show that the three as-prepared nanoparticles were uniformly dispersed on the surface of carbon,and the aver-age size was between 8 nm and 1 7 nm.The results of the electrochemical characterizations show that the direct oxidation of BH-4on Au0.5-Cu1-Ni1/C nanoparticles was the most negative,the number of transfer electrons was 6.0 on Au0.5-Cu1-Ni1/C nanoparticles,which was the most due to the oxidation of BH-4,about 6 times than on Au/C nanoparticles.Although the content of no-ble metal Au in Au1-Cu4/C and Au0.5-Cu1-Ni1/C catalysts was the same(20%),the ternary alloy nanocatalyst Au0.5-Cu1-Ni1/C had a smaller charge transfer resistance of 331.9 Ω/cm2,the cata-lytic activity order of the three nano-particles was:Au0.5-Cu1-Ni1/C,Au1-Cu4/C,Au/C.There-fore,it is necessary to develop ternary alloy Au-Cu-Ni/C catalyst based on binary alloy catalyst Au-Cu/C.