【摘要】 在固定床反应器中,对一氧化碳气相催化偶联合成草酸二乙酯的反应体系进行了人为飞温,两次飞温过程分别为:反应温度从120℃飞温到400～500℃和1000～1200℃,考察飞温后催化剂的活性。对飞温失活催化剂进行再生后,测定了再生催化剂的活性。利用XPS技术对催化剂表面元素进行分析测试,发现第一次催化剂飞温失活的主要原因是催化剂活性组分Pd被氧化所致,而第二次催化剂飞温失活的主要原因是催化剂活性组分Pd被其它元素所覆盖。对第一次失活催化剂再生后,其活性可恢复至原来水平,对第二次失活催化剂再生后,其活性仅恢复到原有催化剂活性的50%。更多还原

【Abstract】 Reaction temperatures of CO gaseous phase coupling reaction to diethyl oxalate, in fixed bed reactor, were artificially runaway twice from the optimum 120 ℃ to 400～500 ℃ and 1000～1200 ℃ respectively. Activity of catalysts after temperature runaway was measured and compared with that operated at optimum reaction temperature of 120 ℃. Temperature runaway led to decrease in catalytic activity. Deactivated catalysts of two cases were further analysed by XPS. The cause of the first deactivation was due to the oxidation of the Pd catalyst component, and that of the second deactivation was due to covering of active Pd by other elements. Catalytic activity of deactivated catalysts after regeneration could be fully recovered from deactivation the in first case, but only 50% of the original could be recovered from deactivation in the second case.更多还原