论文部分内容阅读
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3～11nm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1mol·L-1CH3OH+1mol·L-1NaOH条件下,Pd/C对甲醇氧化最高峰电流密度为890mA·mg-1,约为Pt/C的66%,Ni/C对甲醇氧化最高峰电流密度为6.3mA·mg-1,仅为Pt/C的0.46%。
Five kinds of nano-metal carbon catalysts of M / C (M = Pt, Pd, Ni, Ag and Au) were prepared by chemical reduction method. The crystal structure, surface composition and valence state of the catalysts were characterized by XRD and XPS. The microstructure of the catalyst was observed by TEM. The electrocatalytic activity of different catalysts for methanol oxidation was determined by cyclic voltammetry. The results showed that the size of nano-metal catalyst in the catalyst ranged from 3 to 11 nm with high purity and relatively uniform distribution on the surface of the support. The Pd / C catalyst had a good catalytic effect on methanol oxidation. The oxidation of methanol / A certain activity, while Ag / C and Au / C have almost no activity. Under the conditions of 1mol·L-1CH3OH + 1mol·L-1NaOH, the highest peak current density of Pd / C for methanol oxidation was 890mA · mg-1, which was about 66% of that of Pt / C. The density of 6.3mA · mg-1, only 0.46% Pt / C.