Goudarzi Ehsan, Asadi Reza, Darian Jafar Towfighi, Shahbazi Kootenaei Amirhossein
Department of Chemical Engineering, Tarbiat Modares University P. O. Box 14115-143 Tehran Iran.
Department of Chemical Engineering, Tarbiat Modares University P. O. Box 14115-143 Tehran Iran
RSC Adv. 2019 Apr 16;9(21):11797-11809. doi: 10.1039/c8ra10598g. eCollection 2019 Apr 12.
Titanate nanotube supported molybdena was evaluated as a catalyst in the oxidative dehydrogenation of propane to propylene. The synthesized titanate nanotubes with high specific surface area were prepared by a hydrothermal method. The characterization of pristine nanotubes was performed XRD, Raman, SEM, TEM and BET. The presence of hydrogen titanate nanostructure was confirmed in the bare support. Incipient wetness impregnation method was used to prepare MoTNT- ( = 5, 10, and 15 wt% molybdena). The as-prepared catalysts' characterization was investigated using Raman, XRD, SEM, EDS, TEM, BET, TGA, and CHNS. Furthermore, H-TPR was performed to explore reducibility of the catalysts. XRD and Raman results indicated development of the anatase phase in MoTNT- catalysts upon calcination, along with specific surface area loss according to BET. Study of the catalytic performance of the samples showed an increase in catalytic activity and a significant drop in propylene selectivity with rising molybdena content. The maximum yield of propylene (about 9.3%) was obtained in 10 wt% of Mo content. The effect of potassium loading as a promoter in K/MoTNT-10 catalyst was also explored through characterization of the surface molybdena species and catalytic performance. Due to the presence of potassium, propylene yield increased from 9.3% to 11.3% at 500 °C. The stabilities of both catalysts were considered for 3000 min and showed only slight drops in propane conversion and propylene selectivity.
对钛酸盐纳米管负载的钼酸进行了评估，以作为丙烷氧化脱氢制丙烯的催化剂。通过水热法制备了具有高比表面积的合成钛酸盐纳米管。采用XRD、拉曼光谱、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和比表面积分析仪（BET）对原始纳米管进行了表征。在裸载体中证实了钛酸氢纳米结构的存在。采用初湿浸渍法制备了MoTNT-（钼含量分别为5 wt%、10 wt%和15 wt%）。使用拉曼光谱、XRD、SEM、能谱仪（EDS）、TEM、BET、热重分析仪（TGA）和元素分析仪（CHNS）对所制备的催化剂进行了表征。此外，还进行了程序升温还原（H-TPR）实验以探究催化剂的还原性。XRD和拉曼光谱结果表明，煅烧后的MoTNT-催化剂中锐钛矿相有所发展，同时根据BET结果，比表面积有所损失。对样品催化性能的研究表明，随着钼含量的增加，催化活性提高，但丙烯选择性显著下降。在钼含量为10 wt%时，丙烯的最大产率约为9.3%。还通过对表面钼物种的表征和催化性能研究了钾负载作为K/MoTNT-10催化剂促进剂的作用。由于钾的存在，在500℃时丙烯产率从9.3%提高到了11.3%。对两种催化剂的稳定性进行了3000分钟的考察，结果表明丙烷转化率和丙烯选择性仅略有下降。
