MCM-56分子筛催化苯与丙烯液相烷基化反应性能

在晶化釜内动态水热合成了MCM-56分子筛, 采用过氧化氢回流处理方法脱除模板剂, 获得了高比表面积分子筛MCM-56[MCM-56(H2O2)]. 采用XRD, N2气吸附-脱附, NH3-TPD和FTIR等对其结构和酸性进行表征, 考察了HMCM-56(H2O2)分子筛在苯与丙烯液相烷基化合成异丙苯中的催化性能. 研究结果表明, 过氧化氢回流处理能够有效去除模板剂. 与焙烧去除模板剂的HMCM-56(C)相比, HMCM-56(H2O2)分子筛的BET比表面积达到563 m2/g, 外表面积提高近2倍. 酸性表征说明, 与HMCM-56(C)相比, HMCM-56(H2O2)的总酸量较高而酸强度分布不变. 在苯与丙烯液相烷基化反应中, HMCM-56(H2O2)分子筛表现出更好的低温活性和更高的异丙苯选择性.     

铜掺杂钙铝水滑石催化氧化异丙苯制备异丙苯过氧化氢

采用共沉淀法制备了铜掺杂钙铝水滑石Ca₄Cu _x Al-LDHs（x=0,0.1,0.3,0.5,0.8,1.0）,并对其催化异丙苯液相氧化制备异丙苯过氧化氢的活性进行了研究。采用X射线衍射、傅里叶红外光谱、扫描电子显微镜和热分析等手段对Ca₄Cu _x Al-LDHs进行了表征,制备的Ca₄Cu _x Al-LDHs保留了水滑石的片层状结构,铜的掺杂使孔径变小,比表面积增大。当进料比（催化剂/异丙苯）为7.5 mg/mL,反应温度85 ℃,氧气流速为15 mL/min,反应时间7 h,异丙苯的转化率为34.5%,异丙苯过氧化氢的选择性为86.9%,催化剂循环使用5次后,异丙苯的转化率为31.2%,异丙苯过氧化氢的选择性为83.3%。研究为异丙苯过氧化氢开发了新的催化体系。     

Kinetics and thermodynamics of thermal decomposition of synthetic AlPO<Subscript>4</Subscript>·2H<Subscript>2</Subscript>O

Cumene hydroperoxide (CHP) and its derivatives have caused many serious explosions and fires in Taiwan as a consequence of thermal instability, chemical contamination, and even mechanical shock. It has been employed in polymerization for producing phenol and dicumyl peroxide (DCPO). Differential scanning calorimetry (DSC) was used to analyze the thermal hazard of CHP in the presence of sodium hydroxide (NaOH), sulfuric acid (H₂SO₄), and sodium bisulfite (Na₂SO₃). Thermokinetic parameters for decomposition, such as exothermic onset temperature (T ₀ ), maximum temperature (T _max ), and enthalpy (ΔH), were obtained from the thermal curves. Isothermal microcalorimetry (thermal activity monitor, TAM) was employed to investigate the thermal hazards during CHP storage and CHP mixed with NaOH, H₂SO₄, and Na₂SO₃ under isothermal conditions in a reactor or container. Tests by TAM indicated that from 70 to 90 °C an autocatalytic reaction was apparent in the thermal curves. According to the results from the TAM test, high performance liquid chromatography (HPLC) was, in turn, adopted to analyze the result of concentration versus time. By the Arrhenius equation, the activation energy (E _a ) and rate constant (k) were calculated. Depending on the process conditions, NaOH was one of the incompatible chemicals or catalysts for CHP. When CHP is mixed with NaOH, the T ₀ is induced earlier and the reactions become more complex than for pure CHP, and the E _a is lower than for pure CHP.     

木质素催化转化制备异丙苯

Cumene is an important intermediate and chemical in chemical industry.In this work,directional preparation of cumene using lignin was achieved by a three-step cascade process.The mixture aromatics were first produced by the catalytic pyrolysis of lignin at 450℃ over 1% Zn/HZSM-5 catalyst,monocyclic aromatics with the selectivity of 85.7 wt% were obtained.Then,the catalytic dealkylation of heavier aromatics resulted in benzene-rich aromatics with 93.6 wt% benzene at 600℃ over Hβ catalyst.Finally,the cumene synthesis was performed by the aromatic alkylation,giving cumene selectivity of 91.6 C-mol% using the[bmim]Cl-2AlCl₁₃ ionic liquid at room temperature for 15 min.Besides,adding a small amount of methanol to the feed can efficiently suppress the coke yield and enhance the aromatics yield.The proposed transformation potentially provides a useful route for production of cumene using renewable lignin.     

气相色谱法同时测定过氧化氢异丙苯中异丙苯和苯乙酮

建立了气相色谱-氢火焰离子化检测器同时测定过氧化氢异丙苯中异丙苯和苯乙酮含量的方法。样品用正己烷稀释,直接进样1.0μL,经DB-1柱分离后,用氢火焰离子化检测器检测,以保留时间定性,峰面积外标法定量。异丙苯、苯乙酮浓度分别在5.15～721μg/mL、5.8～812μg/mL范围内与峰面积呈良好线性关系,相关系数r分别为0.9997、0.9993。样品加标回收率在96.31%～101.2%之间,相对标准偏差在1.04%～2.17%之间。该法简便、快速,可用于过氧化氢异丙苯产品的质量控制。     

Synthesis of Cumene from Lignin by Catalytic Transformation

Cumene is an important intermediate and chemical in chemical industry.In this work,directional preparation of cumene using lignin was achieved by a three-step cascade process.The mixture aromatics were first produced by the catalytic pyrolysis of lignin at 450℃ over 1% Zn/HZSM-5 catalyst,monocyclic aromatics with the selectivity of 85.7 wt% were obtained.Then,the catalytic dealkylation of heavier aromatics resulted in benzene-rich aromatics with 93.6 wt% benzene at 600℃ over Hβ catalyst.Finally,the cumene synthesis was performed by the aromatic alkylation,giving cumene selectivity of 91.6 C-mol% using the[bmim]Cl-2AlCl₁₃ ionic liquid at room temperature for 15 min.Besides,adding a small amount of methanol to the feed can efficiently suppress the coke yield and enhance the aromatics yield.The proposed transformation potentially provides a useful route for production of cumene using renewable lignin.     

Polymer supported catalyst for the effective autoxidation of cumene to cumene hydroperoxide

The autoxidation of cumene to cumene hydroperoxide (CHP) in the presence of catalyst which was prepared by adsorbing copper(II) acetate onto polymer support, was investigated. When a styrene-divinylbenzene copolymer with sulfonic acid functional groups was used as a support, the resulting catalyst had no catalytic activity. When a macroreticular acrylic polymer containing carboxylic acid exchange groups was used as a support, an effective catalyst was obtained. In the presence of this catalyst (0.2 g Cu(OAc)₂-BR-0.6 per 10 mL of cumene) at 353 K, the steady autoxidation rate is 84% faster than that initiated with CHP; the selectivity is 99% at 6.8% conversion. The catalyst is stable at 383 K. Furthermore, the catalyzed cumene autoxidation rate increases linearly with copper acetate loading as well as the amount of catalyst. But when the steady autoxidation rate increases, the selectivity to cumene hydroperoxide reduces, but is still satisfactory. Hence, it is possible to speed up the cumene autoxidation rate by raising the reaction temperature, using catalysts with high metal loading and using more catalyst.     

The initiation properties of 2-cyano-2-propyl hydroperoxide in oxidation processes

The initiating ability of 2-cyano-2-propyl hydroperoxide in the oxidation reaction of cumene by molecular oxygen has been investigated and compared with the initiating ability of cumene hydroperoxide.

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Die Initiierungseigenschaften von 2-Cyano-2-propyl-hydroperoxid bei Oxydations-prozessen

Zusammenfassung Es wurde die Initiierungsfähigkeit des 2-Cyan-2-hydroperoxypropans in der Oxidation von Cumol mit molekularem Sauerstoff untersucht und mit der Initiierungsfähigkeit des Cumolhydroperoxids verglichen.

     

Beiträge zur Chemie des Phosphors. 237. Reaktion von Diphosphan(4) mit Peroxoverbindungen: Bildung von Phosphinophosphinsäure,H2PPH(O)OH,und Bis(phosphino)phosphinsäure, (H2P)2P(O)OH

Contributions to the Chemistry of Phosphorus. 237. On the Reaction of Diphosphane(4) with Peroxo Compounds: Formation of Phosphinophosphinic Acid, H₂PPH(O)OH, and Bis(phosphino)phosphinic Acid, (H₂P)₂P(O)OH Diphosphane(4) reacts with peroxo compounds such as hydrogen peroxide, tetraline hydroperoxide, trifluoroperoxyacetic acid, and cumene hydroperoxide (which is particularly suited for preparative work) at ?30°C to furnish phosphino-phosphinic acid, H₂PPH(O)OH ( 1 ), as the primary product. Compound 1 disproportionates to a major extent in statu nascendi to give phosphanes (above all PH₃) and monophosphorus acids of various oxidation states as well as some bis(phosphino)phosphinic acid, (H₂P)₂P(O)OH ( 2 ). The acids 1 and 2 can be trapped and stabilized as their triethylammonium salts. The structures of these salts have been determined by spectroscopic investigations.