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由NH4Y分子筛制备了HY分子筛,运用N2吸附、NH3-TPD和Py-FTIR等手段表征HY分子筛的物化性能;采用智能重量分析仪(IGA)方法研究了甲基噻吩(2-甲基噻吩、3-甲基噻吩)在HY分子筛上的吸附-脱附行为;采用程序升温脱附-质谱(TPD-MS)联用手段研究了甲基噻吩在HY分子筛上的转化行为。结果表明,在200℃下2-甲基噻吩和3-甲基噻吩在HY分子筛中的强B酸上发生强化学吸附作用,与B酸结合后生成了甲基噻吩的碳正离子结构进而发生了歧化反应、脱烷基反应以及裂化反应;与2-甲基噻吩不同的是,3-甲基噻吩与HY通过一定的氢转移反应生成了3-甲基四氢噻吩,且200℃吸附条件下3-甲基噻吩比2-甲基噻吩更容易发生裂化反应。
HY molecular sieve was prepared from NH4Y molecular sieve. The physicochemical properties of HY molecular sieve were characterized by N2 adsorption, NH3-TPD and Py-FTIR. The effects of methyl thiophene (2-methylthiophene, 3 - methylthiophene) on HY molecular sieve. The conversion behavior of methylthiophene on HY zeolite was investigated by temperature-programmed desorption-mass spectrometry (TPD-MS). The results showed that the strong chemisorption of 2-methylthiophene and 3-methylthiophene on the strong B acid in HY molecular sieve at 200 ℃ and the subsequent formation of the carbenium ion of methylthiophene by B acid The disproportionation reaction, the dealkylation reaction and the cracking reaction. Unlike 2-methylthiophene, 3-methylthiophene and HY are converted to 3-methyltetrahydrothiophene by a certain hydrogen transfer reaction, and the adsorption conditions 3-methylthiophene is more susceptible to cracking than 2-methylthiophene.