I prepared a series of H-ZSM-5 (Si/Al=180) supported Pd/Pt bifunctional catalysts for the hydroisomerization of n-heptane by impregnation and post-solvothermal synthesis. The acidity of the catalyst was analyzed by pyridine infrared and NH3-TPD, and the conclusions were quite different. The specific problems are as follows: NH3-TPD does not observe NH3 desorption at high temperature (>300 ℃), while in pyridine infrared, the difference between B acid and L acid in different materials at high temperature (350 ℃) is not very large. The instructor's understanding is that the addition of metal will not change the acid properties of zeolite. My question is whether the prepared bifunctional catalyst is a material with catalytic effect on NH3. At higher temperature, the adsorbed NH3 decomposes into N2 and H3 on the catalyst, so the mass spectrometry (MS) detector does not detect NH3. The collected signal channel is m/z=16.
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