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本文用XRD和DTA方法研究了钒沉积对超稳Y沸石(USY),以(NH_4)_2SiF_6二次合成方法制得的高硅Y沸石和铈交换的CeHY沸石的热稳定性和水热稳定性的影响.随着钒沉积量增加,这三种Y沸石的相对结晶度和晶格破坏温度均下降.其中SY沸石的相对结晶度和晶格破坏温度始终保持最高.高温水蒸气处理对钒沉积沸石样品的破坏作用更为严重.当钒含量达到2m%时,在700℃水蒸气处理后,SY和USY沸石的晶格完全破坏.浸渍钒的CeHY沸石稳定性更差,在400℃水蒸气处理晶格已遭受破坏.本文还讨论了沸石的钒中毒机理.根据实验结果推测V_2O_5与RE_2O_3和Al_2O_3形成低共熔物以及钒酸对沸石的水解作用均能导致沸石晶体破坏,但后者可能是更为有害的,
In this paper, the thermal stability and hydrothermal stability of vanadium deposition on ultra-stable Y zeolite (USY), the high-silica Y zeolite prepared by the secondary synthesis of (NH 4) 2SiF 6 and the cerium-exchanged CeHY zeolite were studied by XRD and DTA methods. With the increase of vanadium deposition, the relative crystallinity and lattice destruction temperature of the three Y zeolites all decreased, in which the relative crystallinity and lattice destruction temperature of SY zeolite remained the highest.Vapor deposition at high temperature affected the deposition of vanadium The destruction of zeolite samples is more serious.When the content of vanadium reached 2m%, the crystal lattice of SY and USY zeolite completely destroyed after water vapor treatment at 700 ℃ .The stability of CeHY zeolite impregnated with vanadium is worse, The crystal lattice has been destroyed.This paper also discusses the mechanism of vanadium poisoning of zeolite.It is speculated that the formation of eutectic V_2O_5 and RE_2O_3 and Al_2O_3 and the hydrolysis of vanadic acid on the zeolite can lead to the destruction of zeolite crystals according to the experimental results, Is more harmful,