Cr^(3+)取代的磷钒铬三元杂多化合物K_(13)PV_(12)Cr_2O_(42)·nH_2O催化H_2O_2分解的研究

Catalytic Decomposition of Hydrogen Peroxide of Cr^(3+)-Sub stituted Ternary Heteropoly Compound K_(13)PV_(12)Cr_2O_(42)·nH _2O

在合成一种新的杂多化合物(K13PV12Cr2O42)的基础上,进一步考察了反应温度、过氧化氢起始浓度,以及该杂多化合物作为催化剂时的用量对过氧化氢分解反应的催化作用;并将其与同结构的杂多化合物K7PV12Mo2O42对该反应的催化作用进行了比较。在30～50℃范围内得到了催化反应的速率常数,并由Arrhenius公式计算出反应的活化能约为70.63kJ·mol-1,表明所合成杂多化合物对H2O2分解具有良好的催化性能,也说明Cr3+对V5+的取代有助于改善杂多化合物的催化性能。推导出了H2O2催化分解反应的速率方程。

The catalytic decomposition on hydrogen peroxide via a Cr3+-substituted t ernary heteropoly compound K13PV12Cr2O42·nH2O which w as previously synthesized was studied on varing initial concentration of H2O 2 as well as amount of catalyst at different temperature. The rate constant was obtained from 30～50 ℃. The activation energy was 70.63 kJ·mol-1 whi ch w as smaller than some heteropoly compounds with Keggin structure and K7PV12 Mo2O42·nH2O with the same structure of Bi-Capped-Keggin. It s hows that the titled compound has higher catalytic ability and that the substi tution of low valence transitional-metal to V(Ⅴ) in the structure of heteropol y anion would help to improve the catalytic properties. At the same time, the r ate equation of catalytic reaction was also deduced.