考察了MoBiTeO/SiO2催化剂对丙烷选择氧化制丙烯醛的催化性能,并采用原位拉曼、X射线衍射和X光电子能谱等技术研究了催化剂在反应过程中的结构重组及其对催化性能的影响.实验结果表明,反应前,MoBiTeO/SiO2催化剂主要由Te多钼酸盐物种组成;在570℃和C3H8/O2/N2=1.2/1/4的反应条件下,MoBiTeO/SiO2催化剂中的部分Te组分被深度还原为金属Te而流失,使部分Te多钼酸盐物种进行了结构重组形成了MoO3物种.Te多钼酸盐和MoO3之间的协同作用使催化剂的催化性能提高.
The catalytic performance of MoBiTeO/SiO2 for selective oxidation of propane to acrolein was investigated, and the catalyst was characterized by means of X-ray powder diffraction, in-situ laser Raman spectroscopy, in-situ laser Raman spectroscopy, and X-ray photoelectron spectroscopy. The results showed that Te-polymolybdate species were the main active phase on the fresh catalyst. Under the conditions of 570 ℃ and C3H8/O2/N2 = 1.2/1/4, some Te species in the catalyst were reduced to metal Te which was volatilized during the reaction, and therefore the active surface phase of the catalyst was reconstructed, leading to the formation of MoO3 species. Along with the active surface reconstruction, both the conversion of propane and the selectivity for acrolein were increased, which was attributed to the synergistic effect between Te-polymolybdate and MoO3.