Keggin, Wells-Dawson and Preyssler structured polyoxometalates (POMs) were synthesized by different methodologies. The POMs were used as catalysts for ammoxidation of 2-methylpyrazine. The structural properties of POMs were determined by XRD, SEM, DRIFT, DRUV-vis, H₂-TPR, NH₃-TPD and N₂-physisorption. Preyssler POM sample showed highest 2-methylpyrazine conversion (69%) and 2-cyanopyrazine selectivity (98%) at 380 °C. Superior performance of Preyssler POM could be attributed to its redox behavior and relatively strong acid sites. Large number of ammonium ions in the secondary structure of Preyssler POM could also enhance the transformation of oxygenated 2-methylpyrazine species into 2-cyanopyrazine. A correlation between the amount of ammonium content of POMs and their catalytic ammoxidation activity was obtained.

用不同的方法合成了Keggin，Wells-Dawson和Preyssler结构的多金属氧酸盐（POM）。该POM用作2-甲基吡嗪氨氧化的催化剂。通过XRD，SEM，DRIFT，DRUV- vis，H ₂ -TPR ，NH ₃ -TPD和N ₂来确定POM的结构性质。-物理吸附。Preyssler POM样品在380°C时显示最高的2-甲基吡嗪转化率（69％）和2-氰基吡嗪选择性（98％）。Preyssler POM的卓越性能可归因于其氧化还原行为和相对较强的酸性位。Preyssler POM二级结构中的大量铵离子也可以促进氧化的2-甲基吡嗪类物质向2-氰基吡嗪的转化。获得了POMs的铵含量与其催化氨氧化活性之间的相关性。