In order to improve the catalytic performance of NiO/Nb₂O₅-TiO₂, several kinds of the second metal oxide component MO_x (M = Pd, Co, Ir or Rh) were separately introduced and their effects on the reduction property and catalytic performance were evaluated. The results showed that the reduction temperature of NiO decreased and NiO-Co₃O₄/Nb₂O₅-TiO₂ exhibited the best catalytic performance. The reason for the enhancement of NiO reducibility may stem from the interaction of M with Ni and the hydrogen spillover as confirmed by various characterization techniques including XRD, H₂-TPR, H₂-TPD and XPS.

中文翻译：

---

第二金属成分对Ni -MO _x / Nb ₂ O ₅ -TiO ₂还原由正戊醛直接合成2-丙基庚醇的催化性能的影响

为了提高NiO / Nb ₂ O ₅ -TiO ₂的催化性能，分别引入了几种第二金属氧化物组分MO _x（M = Pd，Co，Ir或Rh），它们对还原性能和评估催化性能。结果表明，NiO的还原温度降低，NiO-Co ₃ O ₄ / Nb ₂ O ₅ -TiO ₂表现出最佳的催化性能。NiO还原能力增强的原因可能是由于M与Ni的相互作用以及氢的溢出，这已通过各种表征技术（包括XRD，H ₂ -TPR，H₂ -TPD和XPS。