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以多壁碳纳米管(MWCNTs)为载体,采用浸渍法制备了H6P2W18O62·nH2O/MWCNTs催化剂,对其进行了FT-IR、EDX、XRD、SEM表征,并以乙酸和正丁醇合成乙酸正丁酯为探针反应,考察了催化剂的酸催化性能,以及反应条件和催化剂重复使用次数对酯化率的影响。结果表明,H6P2W18O62·nH2O/MWCNTs催化活性高于单一组分的H6P2W18O62·13H2O和MWCNTs。该酯化反应的最佳条件为磷钨酸负载量50%,催化剂用量(按反应体系总质量计)0.6%,醇/酸摩尔比2,反应温度120℃,反应时间2.0h。此时,酯化率可达97.1%。催化重复使用5次后,酯化率仍可达60.9%。
H6P2W18O62 · nH2O / MWCNTs catalysts were prepared by impregnation method using multi-walled carbon nanotubes (MWCNTs) as support. The catalysts were characterized by FT-IR, EDX, XRD and SEM. For the probe reaction, the acid catalytic properties of the catalyst, as well as the reaction conditions and the number of repeated catalyst on the esterification rate. The results showed that the catalytic activity of H6P2W18O62 · nH2O / MWCNTs was higher than that of H6P2W18O62 · 13H2O and MWCNTs. The optimal conditions for the esterification reaction were 50% of phosphotungstic acid loading, 0.6% of catalyst (total mass of the reaction system), molar ratio of alcohol to acid of 2, reaction temperature of 120 ℃ and reaction time of 2.0h. At this point, the esterification rate of up to 97.1%. Catalytic re-use 5 times, the esterification rate is still up to 60.9%.