碱性条件下M/C(M=Pt, Pd, Ni, Ag, Au)对甲醇氧化电催化活性的对比研究

用化学还原法制备了M/C(M=Pt, Pd, Ni, Ag, Au) 5种纳米金属碳截催化剂，用XRD、XPS分别表征活性物的晶相结构、表面组成和价态形式，用TEM观察催化剂微观形貌，用循环伏安法测定不同催化剂对甲醇氧化的电催化活性。结果表明，催化剂中的纳米金属粒径在3~11 nm之间，纯度较高，在载体表面的分布较为均匀；Pd/C催化剂对甲醇氧化有较好的催化作用，Ni/C对甲醇氧化有一定的活性，而Ag/C和Au/C几乎没有活性。在1 mol·L-1CH3OH+1 mol·L-1NaOH条件下，Pd/C对甲醇氧化最高峰电流密度为890 mA·mg-1，约为Pt/C的66%，Ni/C对甲醇氧化最高峰电流密度为6.3 mA·mg-1，仅为Pt/C的0.46%。

Contrast Investigation for Performance of Methanol Electro-catalytic Oxidation of M/C (M=Pt, Pd, Ni, Ag, Au) in Alkaline Media

Five kinds of nano-metal carbon-supported catalysts M/C (M=Pt, Pd, Ni, Ag, Au) were prepared by a chemical reduction method. The crystal structure, surface composition and element valence state were characterized by X-ray diffraction and X-ray photoelectron spectroscopy, respectively, the morphology of the catalysts was observed by TEM, and the electro-catalytic activity to methanol oxidation was measured by cyclic voltammetry. The results show that the nano-particles with high purity are well dispersed on active black carbon and their sizes are from 3 nm to 11 nm; Pd/C catalyst exhibits high activity to methanol electro-oxidation; Ni/C possesses certain activity to methanol oxidation, but Ag/C and Au/C almost do not have activity. In 1.0 mol·L-1CH3OH+1.0 mol·L-1NaOH, the peak current density of Pd/C to methanol oxidation is 890 mA·mg-1, about 66% of that of Pt/C, and the peak current density of Ni/C is 6.3 mA·mg-1, only 0.46% of that of Pt/C.