Immobilization of Polymer-Protected Ultrafine Metal Particles for Catalyst.

rhodium的超精细颗粒的分散，作为由重氟乙醇-水混合物（1：1体积）的rhodium（III）氯化物在甲基丙烯酸酯和N-乙烯基-2-吡咯烷酮共聚物的存在中的1h。Electron microscopy showed that rhodium particles having dimateters 20- 80 A ^^were highly dispersed without coaggregation and their average diameter was 50 A ^^.The ultra\particles of rhodium protected by the copolymmer are treated with polyacrylamide gel having amino groups， resulting in immobilization of the particles on the gel。非流动性在pH值的4-9范围内成功实现。粒子的绑定与凝胶是稳定的，当凝胶中检测到粒子的释放时，混合物在一个广泛的范围内发生了变化（从2到13）。当它被反复用水冲洗时，非移动催化剂也被重新激活了。凝胶-非流动化的rhodium粒子展示了2-22折叠较大的催化活性比1大气压下用于氢化的商用rhodium碳催化剂30 c。

Dispersions of ultrafine particle of rhodium were prepared as dark brown homogeneous solutions by refluxing ethanol-water mixture (1:1 in volume) of rhodium(III) chloride for 1 h in the presence of the methyl acrylate and N-vinyl-2-pyrrolidone copolymer. Electron microscopy showed that rhodium particles having dimateters 20-80A^^゜ were highly dispersed without coaggregation and their average diameter was 50A^^゜.The ultrafine particles of rhodium protected by the copolymer are treated with polyacrylamide gel having amino groups, resulting in immobilization of the particles onto the gel. The immobilization was successfully achieved in the pH region of 4-9. The binding of the particles to the gel was stable, and no release of the particles from the gel was detected when ph of the mixture was changed in a wide range (from 2 to 13) after the immobilization. The immobilized catalyst remained also intact when it was repeatedly washed with water. The gel-immobilized rhodium particles exhibited 2-22 fold larger catalytic activities than a commercial rhodium carbon catalyst for hydrogenation of olefins at 30 c under 1 atm.