载铜球形活性炭的制备及其吸附脱硫性能的研究
Synthesis of spherical activated carbon supported copper catalyst and its performance for adsorptive desulfurization
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摘要: 以122型弱酸性酚醛系阳离子交换树脂为炭前驱体,经过Cu2+交换、炭化和CO2活化等过程制备得到负载金属铜的球形活性炭,对其进行了SEM、XRD、AAS和BET表征,采用动态吸附实验研究了其对模拟汽油中噻吩类硫化物的吸附性能,并且考察了甲苯和环己烯对其吸附性能的影响,对吸附脱硫机理进行了初步研究。结果表明,载铜球形活性炭上Cu以单质形态存在,并主要与硫原子产生配位作用,提高了对噻吩类硫化物的吸附性能,对噻吩(T)、3-甲基噻吩(MT)、2,5-二甲基噻吩(DMT)和苯并噻吩(BT)的饱和硫容依次为0.938、1.230、1.581和3.744 mg/g,吸附选择性依次为T < MT < DMT < BT。模拟汽油中加入甲苯和环己烯后,饱和硫容分别下降了77%和56%,这是甲苯和环己烯通过π电子与Cu发生作用,从而与硫化物产生竞争吸附导致的。Abstract: Phenolic weak acid cation exchange resin was used as carbon precursor to prepare spherical activated carbon supported copper catalyst by ion exchange, carbonization and activation with CO2. The catalyst was characterized by SEM, XRD, AAS and BET. The adsorptive capacities for different sulfur-containing compounds were evaluated by dynamic adsorption experiments and the competitive effects of toluene and cyclohexene were investigated. The mechanism of adsorptive desulfurization was primarily studied as well. The results showed that metals in the spherical activated carbon existed in elemental form and improved the adsorption performance through direct coordination with sulfur atoms. The saturation capacities for thiophene(T), 3-methylthiophene(MT), 2,5-dimethylthiophene(DMT) and benzothiophene(BT) were 0.938, 1.230, 1.581 and 3.744 mg/g, respectively. The adsorptive selectivity increased in the order of T