摘要
K+-SrO-La2O3/ZnO(KSLZ)催化体系具有很好的催化活性.在1073K反应温度下,其C2产率为18.2%,且C2选择性为68.3%.催化剂抗潮能力明显增加,在室温下经长期放置后,催化剂活性稳定.用XRD,CO2-TPD和XPS表征了KSLZ催化剂的体相组成及表面碱性、表面组成和表面活性氧物种.在此基础上讨论了La2O3,SrO和K+各组分对甲烷氧化偶联反应的作用,提出了表面碳酸盐分解生成活性氧物种的可能性.
It was found that KSLZ are quite active for the oxidative coupling of methane. At 1073 K and under conventional reaction conditions, the conversion was 18 2% and the selectivity for C 2 was 68 3%. After a long exposure of the KSLZ catalyst to air (about 30 d) at room temperature, no any change could be observed in its catalytic performance. XRD, CO 2 TPD and XPS techniques were used to characterize the basicity and their active oxygen species. It was shown that the function of K + cations in the KSLZ catalyst can be attributed to its high dispersion on the catalyst surface, an increase in surface basic sites and a creation of active oxygen species, O 2- 2, on the catalyst surface. Meanwhile, with the decrease of Sr species on the catalyst surface, the catalyst is reluctant to absorption of water from air.
出处
《催化学报》
CSCD
北大核心
1996年第6期502-506,共5页
基金
国家自然科学基金
关键词
金属氧化剂
催化剂
甲烷
氧化偶联
KSLZ
Potassium ion
Strontium oxide
Lanthanum oxide
Zinc oxide
Metallic oxide catalyst
Methane
Oxidative coupling