【摘要】 研究了气相环氧丙烷(PO)异构化制烯丙醇反应中碱性Li3PO4催化剂的失活及再生。实验结果表明,在280℃下反应54 h后,因催化剂表面覆盖大量含氢碳物种引起失活,采用煅烧法、水蒸气洗涤法去除催化剂上的积碳,可使催化剂得到再生。通过XRD、FTIR、原位DRIFT、BET、TG、MAS NMR等手段对催化剂进行表征发现,失活Li3PO4催化剂的比表面及孔体积均下降,但催化剂晶型未发生改变,也无新物相生成。积碳分解温度为300~500℃,在350℃下积碳分解所需时间为40~50 min。煅烧法再生的Li3PO4催化剂上PO转化率为90.7%,烯丙醇选择性为89.8%,与新鲜Li3PO4催化剂的活性相近。更多还原

【Abstract】 The deactivation and regeneration of basic lithium phosphate catalyst used in the isomerization of propylene oxide to allyl alcohol w ere studied. The results show ed that the basic lithium phosphate catalyst deactivated after the reaction at 280 ℃ for 54 h,w hich w as due to carbon deposition containing H element. The carbon deposition could be removed by w ashing w ith steam or calcining. The fresh,deactivated and regenerated catalysts w ere characterized by means of XRD,FTIR,in-situ DRIFT,BET,TG and M AS NM R. The specific surface area and pore volume of the deactivated catalyst decreased w ithout the formation of new phase. The decomposition temperature of the carbon deposition w as in the range of 300- 500 ℃ and,at 350 ℃ the decomposition needed 40- 50 min. The conversion of propylene oxide and the selectivity to allyl alcohol on the catalyst regenerated by the calcining reached 90. 7% and 89. 8%,respectively,similar to those on the fresh catalyst.更多还原