西兰花状金@金-尿素络合物用于甲醇氧化反应电催化剂的研究

Study of Broccoli-like Au@Au-Urea Complex for Methanol Oxidation Reaction Electrocatalyst

与铂基催化剂相比,金(Au)因其价格低和抗毒化性能强而在甲醇燃料电池催化剂的设计中引起了大家的广泛关注。采用尿素-过氧化氢溶液为原料,辅助合成了西兰花状金@金-尿素络合物核壳复合物(简写为Au@urea),合成过程中不需要添加任何表面活性剂。在制备过程中,尿素-过氧化氢溶液既可作为还原剂,又为Au纳米颗粒提供了壳层原料。表征结果表明,Au@urea由平均粒径约100 nm的金纳米颗粒组成,金纳米颗粒表面被[Au(urea)_(4)]Cl_(3)·2H_(2O)层包裹。将合成的Au@urea复合物作为电催化剂应用于甲醇氧化反应,在0.5 M KOH和1.0 M CH_(3)OH的电解液中,0.2 V(vs.SCE)电位下的电流密度为15 mA·cm^(-2),高于大多数报道的纳米金基催化剂。此外,由于壳层的存在,Au@urea复合物在甲醇氧化反应中也具有比较好的稳定性。

Gold(Au)has attracted much attention in methanol fuel cells for both low cost and great poison tolerance compared withplatinum catalysts.Here broccoli-like gold nanoparticles coated with gold-urea complexes,named as Au@urea,were synthesized in the urea hydrogen peroxide adduct(UHP)solution without any additional surfactants.During the preparation process,UHP worked both as reducing agent and shell source for Au nanoparticles.The characterization results indicated that Au@urea is composed of gold nanoparticles with average size about 100 nm that are coated by[Au(urea)_(4)]Cl_(3)·2H_(2O)layers.The as-synthesized Au@ureacomplex was applied as electro-catalystfor methanol oxidation reaction.An anode current density of 15 mA·cm^(-2)was obtained at 0.2 V(vs.SCE)in solutions with 0.5 M KOH and 1.0 M CH_(3)OH at a scan rate of 20 mV·s^(-1),which is much higher than those of most reported gold-based catalysts.In addition,the Au@urea complex also had a relatively good stability for methanol electro-oxidation.