焦化苯中噻吩在酸性沸石催化剂上的催化裂解性能

研究了焦化苯中噻吩在酸性沸石催化剂上的催化裂解性能. 结果表明：噻吩在HZSM-5沸石催化剂的作用下被分解生成硫化氢气体逸出,进而达到脱硫的目的. 通过对不同温度和压力下的催化脱硫性能进行考察,认为HZSM-5沸石催化剂对脱除苯中噻吩具有较高的活性及较好的活性稳定性,且温度、压力是影响催化剂活性和稳定性的重要因素. 以含270 mg/L噻吩的焦化苯为原料,在反应温度为320~380℃、反应压力为3.5~6.0 MPa、质量空速为4~12 h-1的条件下,能彻底脱除其中的噻吩.     

CHP-Ⅰ型裂解催化剂的研制

开发的以较小孔径和较高硅铝比的五元环族分子筛为活性组分的 CHP—1型裂解催化剂,用于大庆蜡油或大港直馏柴油的催化裂解制取低碳烯烃具有优良的水热稳定性、优越的低碳烯烃选择性及较高的低碳烯烃产率。从小试到工业试生产证实催化剂制备工艺可行,重复性好,催化剂物化性能亦能满足流化床操作要求。     

Fe/ZSM-5催化剂的酸性与孔隙特性对合成气直接制备芳烃的影响

以多级孔ZSM-5分子筛为载体,通过等体积浸渍法制备了一种双功能铁基催化剂,用于合成气直接制备芳烃。采用硅烷法合成不同硅铝比和介孔孔隙率的多级孔ZSM-5分子筛载体。催化剂的理化性质通过XRD、XRF、BET和HN₃-TPD进行表征。结果表明：具有较高酸性的分子筛有利于提高油相中芳烃的选择性,当载体的硅铝比为40时,在油相中芳烃选择性可达66.9%;通过调节硅烷剂3-氨丙基三甲氧基硅烷（3-APTMS）的加入量来控制分子筛的介孔孔隙率,可使碳氢产物中芳烃的收率大幅度提高。     

含氮杂原子B-Beta分子筛的制备及其对Knoevenagel缩合反应的催化性能

水热合成杂原子B-Beta分子筛,低温氮化二次处理制备N掺杂的新型碱催化剂,利用Knoevenagel缩合反应进行碱性催化性能评价,考察氮化温度、反应时间、不同氮化前驱体及催化剂稳定性对反应的影响.结果表明,采用低温500℃氮化处理的杂原子B-Beta分子筛催化剂具有优异的催化活性,苯甲醛转化率及产物选择性均接近100...     

甲醇制烯烃催化剂研究进展

综述了甲醇制烯烃催化剂的研究进展,从晶体结构、改性方法、催化性能等方面分析了两种重要的甲醇制烯烃催化剂ZSM-5和SAPO-34;并介绍了由上述分子筛开发出的ZSM-5/磷酸铝复合分子筛。     

煤矸石合成纳米4A沸石分子筛的工艺研究

根据所选用煤矸石的成分特点提出了利用煤矸石合成纳米4A沸石分子筛的碱溶提取法,研究了该工艺,并通过试验优化了该工艺的技术参数,即用碳酸钠与煤矸石混合灼烧活化,以4mol／L的NaOH溶液提取硅铝酸钠,晶化温度为90℃,晶化时间为1h,合成并表征了质量性能优良的纳米4A沸石分子筛。     

粉煤灰沸石碱性活化方法研究

粉煤灰是一种主要成分为硅铝酸盐的工业废弃物,粉煤灰沸石合成转化是其高值化应用的一个发展方向。利用碱性试剂活化粉煤灰是粉煤灰合成沸石的重要途径,研究比较了粉煤灰碱性活化合成沸石的干法和湿法工艺,包括水热法、高温熔融水热法和盐熔法的现状、特点、合成机理,并对碱性活化剂氢氧化钠、硅铝比、煅烧条件等影响因素做了分析研究。     

Ethylene epoxidation on Ag catalysts supported on non-porous, microporous and mesoporous silicates

The ethylene epoxidation activity of Ag catalysts supported on non-porous SiO₂, microporous silicalite zeolite and mesoporous MCM-41 and HMS silicates was investigated in the present study in comparison to conventional low surface area -Al₂O₃ based catalysts. The MCM-41 and HMS based catalysts exhibited similar ethylene conversion activity and ethylene oxide (EO) selectivity with the SiO₂ and -Al₂O₃ based catalysts at relatively lower temperatures (up to 230 °C), whereas their activity and selectivity decreased significantly at higher temperatures (≥300 °C). The silicalite based catalyst was highly active for a wide temperature range, similar to the SiO₂ and -Al₂O₃ based catalysts, but it was the less selective amongst all catalysts tested. High loadings of Ag particles (up to ca. 40 wt.%) with medium crystallites size (20–55 nm) could be achieved on the mesoporous materials resulting in very active epoxidation catalysts. The HMS-type silicate with the 3D network of wormhole-like framework mesopores (with average diameter of 3.5 nm), in combination with a high-textural (interparticle) porosity, appeared to be the most promising mesoporous support.     

Computational study on IM-5 zeolite: What is its preferential location of Al and proton siting?

The topological structure of IM-5 zeolite has remained a mystery for nearly 10 years. Stimulated by the recently structural solution of IM-5, we firstly report the computational study on the Al locations, acid sites and acid strength, which are important to understand the catalytic mechanism of IM-5. At the B3LYP/6-31+G(d,p) level, the 8T models were applied. The substitutions of Si by Al atom at 24 inequivalent tetrahedral crystallographic sites and the corresponding H proton localizations were examined by calculating the Al, H substitution energies, proton affinities, the atomic charges on proton and hydroxyl stretching vibrational frequencies. Based on the calculated results it was predicted that the most favorable sites for Al atom substitution in IM-5 were T4, T5, T14, T15 and T19 sites, whereas the least favorable sites were T1, T3, T8, T11, and T16 sites. There are about 40 preferable Al, H locations with relatively high acidity, including the nine strongest acid sites Al19H43 > Al14H18 > Al5H13 > Al4H8 > Al10H26, Al15H26, Al15H37, Al22H45 and Al24H47. The last five sites have equivalent proton affinity values. The numerous Al, H-sites with high acidity may be responsible for the high catalytic ability of IM-5. The calculated results should be helpful for understanding the chemistry of IM-5, the most complicated zeolite material known up to now.     

Modification of acidity of Mo-Fe/HZSM-5 zeolite via argon plasma treatment

The NH₃-TPD characterization was conducted to confirm that the acidity of Mo-Fe/HZSM-5 zeolite could be selectively modified via the glow discharge plasma treatment. The plasma catalyst treatment could totally change the distribution of aromatic products with higher methane conversion compared to the untreated catalyst. Some polycyclic aromatics such as anthracene, pyrene and phenanthrene were also produced over the plasma treated catalyst, in addition to benzene, toluene and naphthalene, which were normally obtained over the untreated catalyst.