摘要
采用XRD、TEM、H2-TPR、Raman、XPS和活性评价等方法,研究了Mg助剂对Co/Mg/HZSM-5催化剂物理化学性质和甲烷部分氧化(POM)制合成气反应性能的影响.研究发现,在Co/HZSM-5催化剂中添加Mg助剂,可有效地提高催化剂的催化活性和稳定性.在750℃和空速1.0×105mL·h-1·g-1反应条件下,Co/Mg/HZSM-5在连续反应30h的实验时间内催化活性稳定不变,而Co/HZSM-5因其活性中心Co0转化生成CoAl2O4非活性相,反应10h后即迅速失活.催化剂表征结果表明,在Co/Mg/HZSM-5催化剂中钴物种除以Co3O4存在外,一部分钴物种还与Mg助剂发生强相互作用生成较难还原的MgCo2O4,由此导致还原后钴金属的分散度较高.关联催化剂表征和活性评价结果,讨论了催化剂结构与性能之间的关系.
The effect of a Mg promoter on the physical and chemical properties, as well as catalytic performance of the Co/Mg/HZSM-5 catalyst for the partial oxidation of methane（POM） to syngas was studied by XRD, H2-TPR, TEM, Raman, XPS and activity measurements. The activity and stability of the Co/HZSM-5 catalyst was effectively improved by Mg modification. At T=750℃ and SV （space velocity）=l.0×10^5 mL·h^-1· g^-1 the Mg-modified catalyst exhibited high activity and good stability during a long run. The unmodified catalyst rapidly deactivated after 10 h on stream. Catalyst deactivation was mainly due to the transformation of CoO into COAl2O4 as indicated by TPR and XPS. For the Co/Mg/HZSM-5 catalyst the Co species, in addition to ones existing as Co3O4, reacted with the Mg promoter to produce MgCo2O4. This structure, after reduction, led to a higher dispersion of Co metal, compared with the Mg-free catalyst. From the results of the characterization and activity measurements, the relationship between catalyst structure and performance was discussed.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2008年第12期2165-2171,共7页
Acta Physico-Chimica Sinica
基金
国家重点基础研究发展规划项目(2005CB221401,2005CB221408)
国家自然科学基金(20433030,20423002)
福建省自然科学基金(2007J0168)资助
