A HIGH-RESOLUTION SOLID-STATE NUCLEAR-MAG NETIC-RESONANCE STUDY OF THE BEHAVIOR OF MODIFYING METALLIC-IONS IN HZSM-5

The behaviour of modifying metallic ions Zn2+, Ga3+ etc. in HZSM-5 is studied with high-resolution solid-state Nuclear Magnetic Resonance us ing Xe-129, Si-29, Al-27 as probes. Experimental results indicate that ion Ga3+ is located mainly on the exterior of HZSM-5 and cannot stabi lize the framework, but ion Zn2+ exists inside channel, replaces proto n's position and stabilize the framework. Both ions Zn2+ and Ga3+ do n ot enter into zeolites framework. The framework dealumination is in ac cordence with the following order: GaHZSM-5>HZSM-5>ZnHZSM-5 much great er than BaHZSM-5c is-approximately-equal-to CaHZSM-5.