Zirconia-supported niobia catalyzed formation of propanol from 1,2-propanediol via dehydration and consecutive hydrogen transfer

Vapor-phase catalytic dehydration of 1,2-propanediol was investigated over Zirconia-supported niobia catalysts. The catalysts exhibit selectivity favoring propanol (approximately 39%) at 85.0% 1,2-propanediol conversion at 290 °C under 1 atm N₂. The ZrNbO catalysts were analyzed by various techniques; the results indicated that the active sites were weak Brønsted acid sites. A dehydration and hydrogen transfer mechanism was also proposed.     

对甲苯璜酸催化合成苯甲醛1，2-丙二醇缩醛

以对甲苯磺酸为催化剂,通过苯甲醛和1,2-丙二醇反应合成了苯甲醛1,2-丙二醇缩醛,通过正交实验优选反应条件,研究了反应物料配比、催化剂用量、反应时间等因素对反应的影响。结果表明,在n(苯甲醛):n(1,2-丙二醇)=1:1.6,催化剂用量为1.0g,环己烷为带水剂,反应时间45min的优化条件下,苯甲醛1,2-丙二醇缩醛的收率可达73.5%。对甲苯磺酸对合成苯甲醛1,2-丙二醇缩醛具有良好的催化活性,催化剂用量少,反应时间短,苯甲醛1,2-丙二醇缩醛收率较高,工艺流程简单,可降低生产成本。因此,对甲苯磺酸是合成苯甲醛1,2-丙二醇缩醛的优良催化剂,具有良好的应用前景。     

H3PWl2O40/Y-β催化苯甲醛1,2-丙二醇缩醛的绿色合成

采用Y-β复合分子筛负载H3PWl2O40为催化剂,对苯甲醛与1,2-丙二醇发生缩合反应合成苯甲醛1,2-丙二醇缩醛进行了研究,考察了催化剂用量、醇醛摩尔比、反应时间、带水剂用量及催化剂重复使用次数等因素对收率的影响。结果表明,该催化剂具有催化性能高,易回收并有较好的重复使用性能等优势。最佳反应条件为：苯甲醛0.1mol,醇醛摩尔比1.2,催化剂用量0.6g,带水剂环己烷用量为10mL,反应40min后收率为92.3％。     

Conversion of biomass to 1,2-propanediol by selective catalytic hydrogenation of lactic acid over silica-supported copper

It is shown that it is possible to produce 1,2-propanediol (a high demand commodity chemical) in high yields via the vapor-phase catalytic hydrogenation of biomass-derived lactic acid. This catalytic process provides an environment-friendly route for the production of 1,2-propanediol from renewable resources. Reaction kinetics measurements were conducted for the vapor-phase hydrogenation of lactic acid over silica-supported copper at total pressures between 0.10 and 0.72 MPa and temperatures between 413 and 493 K. Lactic acid is hydrogenated over Cu/SiO₂ under these reaction conditions to predominately 1,2-propanediol, with formation of smaller amounts of 2-hydroxy propionaldehyde, propionic acid, and propyl alcohols. Deactivation of the Cu/SiO₂ catalyst does not appear to be significant under these reaction conditions. The production of 1,2-propandiol is favored at higher hydrogen partial pressures. At 473 K and a hydrogen partial pressure of 0.72 MPa, complete conversion of lactic acid was observed, with 88 mol% of the lactic acid converted to 1,2-propanediol. A reaction scheme for lactic acid conversion is proposed involving the dissociative adsorption of lactic acid to form an adsorbed -hydroxy acyl species that undergoes successive hydrogenation steps to form adsorbed 2-hydroxy propionaldehyde species and then adsorbed -hydroxy alkoxy species. These alkoxy species react with surface hydrogen to form 1,2-propanediol. The formation of 2-hydroxy propionaldehyde appears to be in equilibrium with 1,2-propanediol at the reaction conditions of the present study.     

固体超强酸SO_4^2-/ZrO_2催化合成苯甲醛缩1,2-丙二醇

以苯甲醛和1,2-丙二醇为原料,在固体超强酸SO24-/ZrO2催化下合成了苯甲醛缩1,2-丙二醇,考察了物料配比、反应时间、催化剂用量、带水剂用量等因素对反应的影响。结果表明,固体超强酸SO24-/ZrO2对合成苯甲醛缩1,2-丙二醇具有良好的催化活性,在苯甲醛用量为0.15mol、n（苯甲醛）∶n（1,2-丙二醇）为1∶1.3、反应时间为60min、催化剂SO24-/ZrO2用量为反应物总质量的0.9%、带水剂环己烷用量为20mL的最佳合成工艺条件下,苯甲醛缩1,2-丙二醇的收率达95.62%、纯度大于99.0%。     

固体超强酸SO42-/ZrO2催化合成苯甲醛缩1,2-丙二醇

以苯甲醛和1,2-丙二醇为原料,在固体超强酸SO24-/ZrO2催化下合成了苯甲醛缩1,2-丙二醇,考察了物料配比、反应时间、催化剂用量、带水剂用量等因素对反应的影响。结果表明,固体超强酸SO24-/ZrO2对合成苯甲醛缩1,2-丙二醇具有良好的催化活性,在苯甲醛用量为0.15mol、n(苯甲醛)∶n(1,2-丙二醇)为1∶1.3、反应时间为60min、催化剂SO24-/ZrO2用量为反应物总质量的0.9%、带水剂环己烷用量为20mL的最佳合成工艺条件下,苯甲醛缩1,2-丙二醇的收率达95.62%、纯度大于99.0%。     

磷钨酸催化合成缩醛(酮)

以磷钨酸为催化剂,对苯甲醛、丁醛、丁酮与二元醇(乙二醇,1,2 丙二醇)为原料合成6种缩醛(酮)的反应条件进行了研究,较系统地研究了醛/酮与二元醇量比、催化剂用量、反应时间诸因素对收率的影响。结果表明,在醛/酮与二元醇(乙二醇,1,2 丙二醇)的投料摩尔比为1∶1 75,催化剂的用量占反应物料总质量的1 5%,反应时间1h条件下,6种缩醛(酮)的收率为55 2%～79 0%。     

Efficient and selective conversion of glycidol to 1,2-propanediol over Pd/C catalyst

The present work deals with the catalytic hydrogenolysis of glycidol to 1,2-propanediol. Reactions were carried out in a closed steel reactor using noble metal based heterogeneous catalysts (Pd, Rh, Pt) under hydrogen pressure (1–8 bars) in the temperature range of 25–140 °C. Pd/C shows the highest glycidol conversion (96%) under solvent free conditions after 24 h with high selectivity to 1,2-propanediol (93%). The effect of the solvent was also investigated and it was demonstrated that ethanol reduces drastically oligomer production enhancing selectivity up to 99% with a significant reaction time reduction (6 h). The Pd/C catalyst shows high recyclability and could be reused several times (9 cycles) without losses in activity and selectivity.     

硫酸高铈催化合成苯甲醛1,2-丙二醇缩醛

以苯甲醛和1,2-丙二醇为原料,在硫酸高铈的催化下,合成了苯甲醛1,2-丙二醇缩醛,研究了物料配比、催化剂用量、反应时间等因素对产品收率的影响。实验表明,硫酸高铈是合成苯甲醛1,2-丙二醇缩醛的良好催化剂,在n(苯甲醛)∶n(1,2-丙二醇)=1∶1.5,催化剂用量为反应物料总质量的0.95%,带水剂环己烷10 mL,反应时间60 m in的条件下,苯甲醛1,2-丙二醇缩醛的收率可达91.10%。催化剂重复使用4次仍保持较高催化活性,产品经气相色谱定量分析,纯度>98.0%。     

Interaction between Pd and Cu nanoparticles in bimetallic CuPdx nanoparticles and its impact on oxidation of 1,2-propanediol to aliphatic acids

Bimetallic CuPd_x nanoparticles synthesized by the wet chemical reduction method were used as the catalysts in the catalytic oxidation of 1,2-propanediol with gaseous oxygen to aliphatic acids. The palladium and copper nanoparticles in the bimetallic CuP dxnanoparticles had an alloying trend. The catalytic activity of the palladium nanoparticles in the bimetallic CuP dxnanoparticles was enhanced by the interaction between the palladium and copper nanoparticles. When the bimetallic CuPd_7 nanoparticles catalyzed the oxidation of 1,2-propanediol in an alkaline aqueous solution at 100℃ for 3h, lactic, formic, and acetic acids were dominantly produced with the total selectivity of above 99% at the 1,2-propanediol conversion of 85.9%. The simulation of the reaction kinetic equation on the CuPd_7 catalyst showed that the reaction activation energy was 29.4kJ·mol~(-1), indicating that the bimetallic CuPd_7 nanoparticles had a high catalytic activity in the oxidation reaction between 1,2-propanediol and gaseous oxygen.     

Production of acrolein from glycerol over silica-supported heteropoly acids

Dehydration of glycerol to produce acrolein was performed over several solid acids. Supported heteropoly acids were effective as a catalyst for the dehydration of glycerol. The catalytic activity depended on the types of heteropoly acid and on the size of the mesopores in the silica support. Silicotungstic acid supported on silica with mesopores of 10 nm showed the highest catalytic activity with the acrolein selectivity of >85 mol% at an ambient pressure and 275 °C.     

十二烷基磺酸铁催化合成苯甲醛1,2-丙二醇缩醛

以十二烷基磺酸铁为催化剂,苯甲醛、1,2-丙二醇为原料,研究合成了苯甲醛1,2-丙二醇缩醛.分别考察了反应时间、催化剂用量、原料配比、带水剂用量等条件对产物收率的影响.结果表明:十二烷基磺酸铁是合成苯甲醛1,2-丙二醇缩醛的良好催化剂,在n(苯甲醛):n(1,2-丙二醇)=1.0∶1.3,催化剂用量为反应物料总质量的1...     

氨基磺酸催化合成丁醛1,2-丙二醇缩醛

以氨基磺酸为催化剂,对以正丁醛和1,2-丙二醇为原料合成丁醛1,2-丙二醇缩醛进行了研究。较系统考察了醛醇摩尔比、催化剂的用量、反应时间、带水剂诸因素对缩醛反应的影响。实验结果表明,丁醛为0.2mol,n（丁醛）∶n（1,2-丙二醇）=1∶1.5,氨基磺酸1g,带水剂环己烷15mL,反应时间为60min时,产品的收率可达56.14%。     

Cu基催化剂催化甘油氢解制备丙二醇

在间歇釜式反应器中考察Cu基催化剂在不同酸性条件下的甘油催化氢解反应性能,采用γ-Al₂O₃、SiO₂和SiC酸碱性不同的载体研究催化剂催化活性和选择性的影响,结果表明,3种载体的Cu基催化剂均对1,2-丙二醇的生成有较高的催化活性和选择性,但只有弱酸性SiO₂为载体时生成1,3-丙二醇。研究在底物中添加H₂SO₄（B酸）对甘油氢解反应性能的影响,发现质子酸的存在有利于1,3-丙二醇的生成,但易导致副反应发生,使1,2-丙二醇选择性大幅降低。研究用磷钨酸改性的Cu/SiO₂催化剂对甘油氢解反应的催化活性的影响,发现磷钨酸的加入有利于甘油氢解为1,3-丙二醇,且酸性越强,越容易发生副反应。随着Cu/HWP/SiO₂催化剂焙烧温度的升高,酸性减弱,丙二醇选择性提高,推测出质子酸作用下Cu基催化剂的甘油氢解反应机理。     

Cu/boehmite: A highly active catalyst for hydrogenolysis of glycerol to 1,2-propanediol

Small Cu clusters (~ 1 nm) were highly dispersed over boehmite via an aqueous chemical reduction method. In comparison with Cu/γ-Al₂O₃, Cu/SiO₂ and Ru/C catalyst, Cu/boehmite catalyst showed the highest conversion and selectivity of 1,2-propanediol in the hydrogenolysis of glycerol. The good conversion and selectivity are ascribed to the small size of Cu metal clusters and the Lewis acid sites of boehmite, which provides high surface concentrations of active metal sites without CC bond cleavage activity and promotes the dehydration of glycerol to acetol as the intermediate of 1,2-propanediol, respectively.     

A multi-functional Ru Mo bimetallic catalyst for ultra-efficient C3 alcohols production from liquid phase hydrogenolysis of glycerol

Ru and Mo bimetallic catalysts supported on active carbon modified by phosphotungstic acid (PW) were designed and applied in glycerol hydrogenolysis reaction. The physicochemical properties of the catalysts were characterized and the presence of active sites was investigated from the perspective of the glycerol hydrogenolysis performance. The MoO_x is highly selective for the C—O bond cleavage of glycerol molecules, which can reasonably regulate the strong C—C bond cleavage activity of Ru nanoparticles. By using sequential deposition of Ru and Mo supported on mesoporous PW-C, the characterization results show that the combination of isolated low-valence MoO_x with metal Ru particles can form “MoO_x-Ru-PW”, which provides highly catalytic activity toward C—O bond cleavage, selectively producing more C3 alcohols (mainly 1,2(3)-propanediol). The glycerol conversion of 1% Mo/Ru/PW-C catalyst was 59.6%, the selectivity of C3 alcohol was 96.1%, and the selectivity of propanediol (1,2(3)-propanediol) was 94.9%. It is noteworthy that the selectivity of 1,3-propanediol reached 20.7% when the PW was 21.07% (mass). This study provides experimental evidence for the tandem dehydration and hydrogenation mechanism of the multifunctional Mo/Ru/PW-C catalyst.     

磺化硅胶催化合成苯甲醛-1,2-丙二醇缩醛

以磺化硅胶为催化剂,苯甲醛和1,2-丙二醇为原料,合成苯甲醛-1,2-丙二醇缩醛.研究了磺化硅胶催化剂用量、原料配比和回流时间对收率的影响.最佳反应条件为:苯甲醛用量0.05 mol,n(苯甲醛)∶n(1,2-丙二醇)=1.0∶1.5,催化剂用量0.2g,带水剂环己烷用量8.0 mL,反应时间80 min,苯甲醛-1,...     

碘掺杂聚苯胺催化合成丁醛1，2-丙二醇缩醛

报道了单质碘掺杂聚苯胺催化剂I2/PAn的制备,采用正交试验探讨了合成丁醛1,2-丙二醇缩醛的影响因素.实验结果表明,对丁醛1,2-丙二醇缩醛的收率影响最大的是催化剂用量,其次是反应时间、带水剂用量和醛醇物质的量比.碘掺杂聚苯胺催化剂催化合成丁醛1,2-丙二醇缩醛的适宜的反应条件是n(正丁醛):n(1,2-丙二醇)=1:1.5,催化剂用量为反应物料总量的0.20%,带水剂环己烷的用量为4 mL,反应时间1.0 h.在优化条件下,产品收率可达73.8%.     

磷钨钼杂多酸掺杂聚苯胺催化合成丁醛1,2-丙二醇缩醛

以磷钨钼杂多酸掺杂聚苯胺为催化剂,通过丁醛和1,2-丙二醇反应合成了丁醛1,2-丙二醇缩醛。考察了醛醇物质的量比、催化剂量及反应时间诸因素对产品收率的影响,确定适宜反应条件为:n(丁醛):n(1,2-丙二醇)=1:1.6,催化剂量为反应物料总质量的1.2%,用环己烷作带水剂,反应时间1.0h。在此反应条件下,丁醛1,2-丙二醇缩醛收率可达95.6%。     

TiSiW_(12)O_(40)/TiO_2催化合成异丁醛1,2-丙二醇缩醛

以固载杂多酸盐TiSiW12 O40 /TiO2 为多相催化剂 ,对以异丁醛和 1,2 -丙二醇为原料合成异丁醛 1,2 -丙二醇缩醛的反应条件进行了研究。实验表明 :TiSiW12 O40 /TiO2 是合成异丁醛 1,2 -丙二醇缩醛的良好催化剂 ,较系统地研究了醛醇摩尔比、催化剂用量、反应时间诸因素对收率的影响。最佳反应条件为 :n(异丁醛 ) :n( 1,2 -丙二醇 ) =1:1.5 ,催化剂用量为反应物料总质量的 0 .5 % ,环己烷为带水剂 ,反应时间 1.0h。上述条件下 ,异丁醛 1,2 -丙二醇缩醛的收率可达 80 .2 % .