ABSORPTION-SPECTRUM AND SOME CHEMICAL-REACTIONS OF COLLOIDAL PLATINUM IN AQUEOUS-SOLUTION
ABSORPTION-SPECTRUM AND SOME CHEMICAL-REACTIONS OF COLLOIDAL PLATINUM IN AQUEOUS-SOLUTION
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DOI：
10.1021/j100038a053
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发表时间：
1995-09-21
影响因子：
--
通讯作者：
MALOW, M
中科院分区：
文献类型：
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作者：
HENGLEIN, A;ERSHOV, BG;MALOW, M
在 10(-3) M 聚磷酸钠（2 x 10(-4) 至 5 x 10(-3) M）和 10(-2) M 甲醇存在下，PtCl42- 发生放射分解还原，产生不规则形状的胶体 Pt 颗粒，直径为 10-30 埃（“放射分解”胶体）。 PtCl42- 的还原部分是自催化的。在 5 x 10(-4) M 聚丙烯酸钠或多磷酸钠存在下，水合络合物 (PtCl2(H2O)(2) 和 PtCl3(H2O)(-) 被氢还原，形成规则形状的胶体颗粒，直径 50-80 埃（“氢”胶体）。“放射分解”和“氢”的吸收光谱和 将“氢”胶体与先前报道的使用柠檬酸盐或聚（乙烯醇）作为稳定剂制备的胶体的光谱进行比较。目前制备的胶体的光谱在 215 nm 处具有预测的最大吸收。 Pt 颗粒倾向于形成团簇，其吸收光谱相当平坦，最大值在 260 nm 处。描述了新胶体的一些反应，并将它们的反应性与现有胶体的反应性进行了比较 通过柠檬酸盐还原 PtCl62- 制备的胶体。各种胶体对O-2、H-2和Au(CN)(2)(-)的反应性以及催化丙醇-2自氧化的能力存在显着差异。这些差异是根据颗粒尺寸和颗粒表面氧化态的差异来讨论的。
The radiolytic reduction of PtCl42- in the presence of 10(-3) M sodium polyphosphate (2 x 10(-4) to 5 x 10(-3) M) and 10(-2) M methanol yields colloidal Pt particles of irregular shape, 10-30 Angstrom in diameter (''radiolysis'' colloid). The reduction of PtCl42- is partly autocatalytic. The reduction of the aquated complexes, (PtCl2(H2O)(2) and PtCl3(H2O)(-), by hydrogen in the presence of 5 x 10(-4) M sodium polyacrylate or polyphosphate leads to colloidal particles of regular shape, 50-80 Angstrom in diameter (''hydrogen'' colloid). The absorption spectrum of the ''radiolysis'' and ''hydrogen'' colloids is compared to the previously reported spectra of colloids which were prepared using citrate or poly(vinyl alcohol) as stabilizer. The spectra of the presently prepared colloids have the predicted absorption maximum at 215 nm. The Pt particles tend to form clusters, whose absorption spectrum is rather flat with a maximum at 260 nm. A few reactions of the new colloids are described and their reactivities compared to that of a colloid prepared by citrate reduction of PtCl62-. Significant differences in the reactivity toward O-2, H-2, and Au(CN)(2)(-) exist between the various colloids as well as in their ability to catalyze the autoxidation of propanol-2. The differences are discussed in terms of differences in particle size and in the oxidation state of the particle surface.