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采用等体积浸渍法制备了H3PW12O40/Al2O3催化剂,在固定床反应器中,考查了催化剂对甘油制备丙烯醛的反应性能以及催化剂的积炭行为,并利用BET、SEM和XRD等对失活前后的催化剂进行了表征。结果表明,负载量为30%时活性最佳,此时甘油转化率100%,丙烯醛的选择性为83.2%。较高的空速有利于减少催化剂上的积炭量,而空速为10 h-1时,催化剂的积炭量最低。而催化剂失活的主要原因是表面积炭引起的,它覆盖在催化剂表面,堵塞了孔道,从而引起了催化剂活性的降低。而积炭可能是由丙烯醛在催化剂上的聚合而产生的。但积炭并没有破坏催化剂的结构,催化剂仍然保持Keggin结构。
The H3PW12O40 / Al2O3 catalyst was prepared by the same volume impregnation method. In a fixed-bed reactor, the reaction performance of the catalyst for the acrolein production by glycerol and the carbon deposition behavior of the catalyst were investigated. The BET, SEM and XRD The catalyst was characterized. The results showed that when the loading was 30%, the activity was the best. At this time, the conversion of glycerol was 100% and the selectivity of acrolein was 83.2%. The higher airspeed helps to reduce the amount of coke deposited on the catalyst, while the catalyst has the lowest amount of coke deposition at a space velocity of 10 h-1. The main reason for catalyst deactivation is surface carbon deposition, which covers the surface of the catalyst, blocking the pores, causing a decrease in catalyst activity. Carbon deposition may be caused by the polymerization of acrolein on the catalyst. But coke does not destroy the structure of the catalyst, the catalyst still retains Keggin structure.