摘要
研究了用草酸处理裂化催化剂的活性组分USY型分子筛以及在催化剂基质中添加磷改性的氧化铝等方法对裂化催化剂氢转移反应活性的影响 .实验结果表明 ,酸处理能脱除USY型分子筛孔道中的无定形氧化铝 ,疏通分子筛孔道 ,提高分子筛的氢转移反应活性 ,减少积碳 ;对于含稀土的REUSY型分子筛 ,酸处理首先脱除的是稀土离子 ,降低了分子筛的裂化反应活性 ,但提高了氢转移反应活性 .在催化剂基质中添加磷改性的氧化铝能增加基质的弱酸性中心 ,增加裂化反应的活性中心 ,提高催化剂的裂化及氢转移反应活性 ,同时减少催化剂上的积碳 .
The effects of the oxalic acid-modified USY zeolite and the phosphorus-modified alumina on the activity of the cracking catalyst for hydrogen-transfer reaction were investigated using IR, XRD, microactivity testing (MAT) and resid MAT. Some extra-framework aluminum was removed from the micropore and more acid sites were accessible when the USY zeolite was dealuminated with oxalic acid, while RE 3+ ions were removed firstly when the REUSY zeolite was treated with oxalic acid. The dealuminated USY zeolite showed higher activity for cracking and hydrogen-transfer reaction. The acid strength of the alumina modified with phosphorus was reduced due to the decreased strong Lewis acid sites and the increased weak Brnsted acid sites. When the phosphorus-modified alumina was added into the matrix the cracking catalyst had a higher hydrogen-transfer activity and a lower coke yield. Both acid-modified USY zeolite and phosphorus-modified alumina were suitable for being used as the olefin-reducing cracking catalysts.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2004年第3期227-230,共4页
关键词
裂化催化剂
氢转移反应
USY分子筛
氧化铝
改性
草酸
磷
cracking catalyst, hydrogen-transfer reaction, USY zeolite, alumina, modification, oxalic acid, phosphorus
