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利用X射线衍射(XRD),X射线光电子能谱(XPS)及活性测试对铈钛复合氧化物的结构及催化脱硫特性进行了研究。结果表明:当铈-钛摩尔比(n(Ce)/n(Ti))≥5:5时,铈钛复合氧化物形成固溶体;当n(Ce)/n(Ti)=7:3(即Ce_(0.7)Ti_(0.3)O_2)时,具有最佳的催化脱硫效果;500°C下SO_2的转化率达到93%,单质硫的产率达到99%。根据Ce_(0.7)Ti_(0.3)O_2的活性测试曲线发现:未经预处理的Ce_(0.7)Ti_(0.3)O_2约10 min后开始逐渐被反应气体活化,并在60 min后达到稳定活化状态。通过对不同反应时间下所得Ce_(0.7)Ti_(0.3)O_2进行XPS分析发现:CeO_2为活性物质,在反应过程中形成Ce~(4+)/Ce~(3+)氧化还原电对和活性氧空位,而Ti O_2仅起到稳定催化剂结构的作用。Ce_(0.7)Ti_(0.3)O_2催化SO_2+CO反应48 h后未出现硫化现象,始终保持结构的稳定,表现出较好的抗硫中毒性能。
The structure and catalytic desulfurization of cerium-titanium composite oxide were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and activity test. The results show that the cerium-titanium composite oxide forms a solid solution when the molar ratio of cerium to titanium (n (Ce) / n (Ti)) is 5: 5, Ce 0.7 Ti 0.3 O 2), the best catalytic desulfurization effect was obtained. The conversion of SO 2 reached 93% at 500 ° C, and the yield of elemental sulfur reached 99%. According to the activity curve of Ce (0.7) Ti 0.3 O 2, it was found that the Ce 0.7 Ti 0.3 O 2 was gradually activated by the reaction gas after about 10 min and reached a stable activation state after 60 min . Through the XPS analysis of Ce 0.7 Ti 0.3 O 2 obtained at different reaction time, it was found that CeO 2 was the active material, and the formation of Ce 4+ / Ce 3+ redox couple and activity during the reaction Oxygen vacancies, while TiO 2 only plays a role in stabilizing the catalyst structure. After 48 h reaction of SO 2 + CO catalyzed by Ce 0.7 Ti 0.3 O 2, no sulfidation occurred, and the structure was stable and showed good anti-sulfur poisoning performance.