气相色谱法研究配位化合物的热稳定性(Ⅶ)——Ni(Ⅱ)、Co(Ⅱ)草酸配合物的热分解及产物的催化性能

STUDIES ON THERMAL STABILITIES OF COORDINATION COMPOUNDS BY GAS CHROMATOGRAPHY(Ⅶ)--THERMAL DECOMPOSITION OF Ni(Ⅱ),Co(Ⅱ)OXALATO COORDINATION COMPOUNDS AND CATALYTIC PROPERTY OF THEIR PRODUCTS

镍(Ⅱ)、钴(Ⅱ)草酸配合物在氢气中热分解时产生CO_(2)和CO,并发生加氢催化反应.CoC_(3)O_(4)和NiC_(2)O_(4)的分解产物CO_(2)加氢活性很快降低;K2O等具有分散金属的作用。CoC_(2)O_(4)/Al_(2)O_(3)和K_(2)[Co(C_(2)O_(4))_(2)]/Al_(2)O_(3)体系具有Al_(2)(C_(3)O_(4))_(3)的分解特征。C_(2)O_(4)^(2-)在Al_(2)O_(3)表面能形成表面配合物,在Al_(2)O_(3)表面Co(Ⅱ)的还原较为困难。

On the basis of gas chromatographic experimental results we here report the hydrogenation reactions of CO and CO_(3)which took place when Ni(Ⅱ),Co(Ⅱ)oxalato coordination compounds decomposed in hydrogen.The catalytic activity of solid products of thermal decomposition of CoC_(2)O_(4)and NiC_(2)O_(4)was determined by the hydrogenation of CO_(2),which decreased rapidly because of the sintering of the metal catalysts.Some decomposition products,such as K2O and K_(2)CO_(3),could disperse metal Co or Ni and prevent the metal catalysts from aggregating.For CoC_(2)O_(4)/Al_(2)O_(3)and K_(2)[Co(C_(2)O_(4))_(2)]/Al_(2)O_(3),the metal-support interaction made it difficult to reduce Co(Ⅱ)and their decomposition curves were somewhat similar to that of Al_(2)(C_(2)O_(4))_(3)at lower temperatures.The infrared spectrum of K2[Co(C2O4)2]/Al_(2)O_(3)implied that a surface coordination compound was formed.