镍基催化剂对乙烷氧化脱氢制乙烯性能的研究

用均匀沉淀法制备了片状复合氧化镍NiMO(M=Li,Sr,Y,Fe,La)催化剂,并研究了其对乙烷氧化脱氢制乙烯的催化性能.采用X射线衍射(XRD)、扫描电子显微镜(SEM)、程序升温还原(H2-TPR)和程序升温脱附(O2-TPD)等方法对镍基催化剂进行了表征.X射线衍射和扫描电子显微镜检测结果表明:助剂的加入对催化剂的形貌影响不大,仍为片状结构;平均粒径为5~10 nm.程序升温还原和脱附表征结果表明:助剂Li,Sr并未进入NiO晶格;而助剂Y,Fe,La与Ni之间具有相互作用,因而影响催化剂的理化性质和催化活性.其中,Fe掺杂的片状氧化镍催化剂对乙烯的选择性和收率均有所改善,340℃时NiFeO催化剂上的乙烯收率可达18.2%.

The performance for oxidative dehydrogenation of ethane to ethylene on nickel-based oxides

Ethylene is an important chemical in petrochemical industry. It can be obtained by oxidative dehy-drogenation of ethane（ODHE）. As a potential low temperature catalyst,NiO prepared by urea precipitation exhibited good ODHE catalytic performance. In this work,the NiMO（M = Li,Sr,Y,Fe,La）nanoflake catalyst was prepared by a homogeneous precipitation method. The Ni-based oxide catalysts were evaluated for the oxidative dehydrogenation of ethane to ethylene and characterized by XRD,SEM,H2-TPR,O2-TPD. XRD and SEM results indicated that the additives didn′t affect the morphology of the catalysts,of which the average size was about 5 ~ 10 nm. The characterization by H2-TPR and O2-TPD showed that the doped Li,Sr did not enter into the NiO lattice,while Y,Fe,La could partially substitute the Ni ion in lattice and had a strong in-teraction with Ni,sequently influenced the physical and chemical properties and catalytic performance of the catalysts. Therein,NiFeO exhibited the best catalytic performance with a 18. 2% ethylene yield at 340 ℃.