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合成MIBK的多元金属催化剂的制备及评价 总被引:3,自引:0,他引:3
采用浸渍法制备了适用于丙酮一步法合成甲基异丁基酮的双功能多金属催化剂。采用间歇高压反应釜在温度为160℃,压力为1.8MPa时,进行了液相丙酮1步法实验评价催化剂。考察了催化剂的载体、催化剂焙烧条件、不同金属活性组成及其含量对催化剂性能的影响。结果表明,以HZSM-5分子筛作为载体,负载Pd、Cu、Zn、Ni以载体质量为基准的质量分数分别为0.2%、0.5%、0.1%、0.8%时所制得的多金属催化剂,其丙酮的转化率为42.7%,MIBK的选择性为95.6%。多金属催化剂与单金属催化剂相比,丙酮的转化率与产品的选择性都大大提高。 相似文献
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《精细化工原料及中间体》2018,(9)
正由丙酮气相一步法合成甲基异丁基酮和二异丁基酮的方法,涉及一种化工溶剂。该方法使用Pd/MgO-Al2O3-ZrO2催化剂,组成为:Pd:1wt%,MgO:55wt%,Al2O3:10wt%,ZrO2:34wt%,催化剂通过PdMgAlZr四元类水滑石化合物制得。在反应温度(150~200)℃,液空速4.8ml/gcat·h,氢酮摩尔比为1,在固定床反应器中,丙酮转化率为30%~73%,甲 相似文献
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甲基异丁基醇气相催化脱氢制备甲基异丁基酮的工艺研究 总被引:1,自引:0,他引:1
在固定床反应器上研究了自制 CuO/ZnO/Al_2O_3为催化剂,常压下由甲基异丁基醇脱氢制备甲基异丁基酮的反应,得到了较佳的工艺条件:温度240~250℃,甲基异丁基甲醇质量空速1.0~1.5 h~(-1),催化剂还原温度低于240℃。在该条件下,甲基异丁基甲醇的单程转化率最高可达82.2%,甲基异丁基酮选择性达到99.0%。实验结果表明,在实验条件下该催化剂具有较好的稳定性。 相似文献
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以纳米二氧化锆为载体的Pd催化剂制备及还原缩合性能研究 总被引:8,自引:0,他引:8
考察了不同制备方法得到的纳米二氧化锆为载体担载Pd催化剂对丙酮还原缩合的影响。纳米二氧化锆的制备方法对二氧化锆的物理性质和催化性能有较大的影响。不同的沉淀方法、陈化环境制备的纳米ZrO2,对不同的产物有不同的选择性,其中,在母液中373K陈化的二氧化锆为载体的催化剂对二异丁基酮(DIBK)的选择性较高,为61 43%;沉淀剂滴加到盐溶液中得到的二氧化锆为载体的催化剂对甲基异丁基酮(MIBK)的选择性较高,为63 70%。催化剂的酸性和Pd分散度表征结果表明,较高的Pd分散度、合适的酸性有利于MIBK的生成,较高的Pd分散度、较强的酸性有利于DIBK的生成。 相似文献
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采用两段串联固定床反应器,以Co/SiO2 作为F-T合成催化剂,以β分子筛负载金属作为加氢裂解/异构化催化剂,研究了从合成气经F-T反应途径一步法选择性合成汽油馏分异构烷烃的反应性能。结果表明,两段固定床系统的F-T合成产物主要为C1~C10烃,而且异构烷烃的选择性较高(I/C+4≈70%)。同时,钯盐前驱体对0.5%Pd/β的加氢裂解/异构化反应性能有很大影响。保持金属总负载质量分数为0.5%,在Pd/β中引入少量Pt或Ni,可以明显改善催化剂活性和稳定性。 相似文献
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用共沉淀法制备Pd类水滑石催化剂,用固定床管式反应装置测试催化剂对丙酮一步法制备MIBK的催化活性,研究了反应温度、氢酮比、进料液空速及催化剂组成对该反应的影响.在常压下,反应温度为180℃,氢酮摩尔比为1.5,液空速为1.20 h-1,选取不同组成的催化剂进行催化性能测试.结果表明:当Mg/Al比为3:1,Pd质量分数是0.2%时,丙酮的转化率达到82.87%,MIBK的选择性为53.56%,收率为44.39%. 相似文献
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《辽宁化工》2016,(12)
以PdMgAl水滑石为前体制备了Pd/MgO-Al_2O_3催化剂,再浸渍K_2CO_3制备了K改性的Pd/MgO-Al_2O_3催化剂,并用于丙酮气相一步法合成甲基异丁基酮反应。采用XRD、BET、TPD、TG-DTA等技术表征了催化剂,并测试了常压下丙酮加氢的活性。结果显示,掺加K后催化剂的酸性减低、碱性增加,提高了催化剂的活性,在反应温度140℃,氢酮比为1∶1,液空速为4.8 m L·g_(cat)~(-1)·h~(-1)时,丙酮的转化率达到49%,MIBK的选择性达到70%。稳定性测试结果表明催化剂反应80 h后活性降低,主要由于积碳引起,550℃焙烧再生后催化剂基本恢复到新鲜催化剂的活性。 相似文献
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Nigamananda Das Didier Tichit Robert Durand Patrick Graffin Bernard Coq 《Catalysis Letters》2001,71(3-4):181-185
Pd/Mg(Al)O samples (0.05 < Pd < 0.5 wt%) were evaluated in the gas phase reaction of acetone with hydrogen to methyl isobutyl ketone (MIBK). The catalysts were prepared by impregnating a calcined Mg–Al layered double hydroxide with Pd acetylacetonate in toluene solution. The highest selectivity to MIBK was achieved with ca. 0.2 wt% Pd and size of Pd particles of ca. 3–5 nm. 相似文献
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《Applied Catalysis A: General》2001,205(1-2):61-69
The surface-phase oxides of niobia on silica substrate ((Nb2O5/SiO2), NS(x)) were prepared and characterized. Such oxides were used as supports for palladium catalysts. The one-step synthesis of methyl isobutyl ketone (MIBK) from acetone and hydrogen in liquid phase was also investigated over Pd/NS(x) catalysts. Experimental results indicate that these catalysts were effective for the formation of MIBK; since little of the parallel by-product of isopropanol (IPA) was formed, these catalysts reached selectivities of 88–92% MIBK and 2–3% IPA at 30–35% conversion. The reactivity of Pd/NS(x) declined obviously with an increase of water content that accumulated in a semi-batch reaction system. The water could be partially expelled and the deactivation of catalysts could be improved by using a fixed bed continuous flow reaction system. 相似文献
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Nb2O5/SiO2 and Pd/Nb2O5/SiO2 catalysts were studied for the liquid phase syntheses of mesityl oxide (MO) and methyl isobutyl ketone (MIBK) in a fixed bed flow reactor (FBR). Catalyst activities as high as 1.7 g/h gcat and selectivities ranging from 93.4 to 100% for MO synthesis were observed. The catalyst activity was found to be a strong function of space velocity likely due to product inhibition. A synergistic effect was observed whereby the catalyst activity for all organic products increased by 22% and the MIBK productivity increased by 20% at 160 °C and WHSV = 8.6 h?1 from the introduction of hydrogen to the reactor. However, the MIBK selectivity was constrained to less than 83.5% due to competing reactions. 相似文献
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Methyl isobutyl ketone (MIBK) was synthesized from acetone (Ac) and hydrogen over Pt-HZSM5 bifunctional catalysts. The reaction
was carried out at 160°C, atmospheric pressure, and with a PH2/PAc molar ratio = 0.33, using a fixed bed and dynamic flow reactor. The results show that catalytic properties and coke formation
largely depend on the ratio between the number of accessible hydro-dehydrogenation sites and the number of theoretical acidic
sites (nPt/nA).
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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以ZSM-5分子筛、铝溶胶、硝酸钯、硝酸铂和水为原料制备分子筛浆料,采用真空抽提-一次涂覆法在堇青石蜂窝陶瓷载体表面制备出PdxPty-ZSM-5/Cordierite整体式催化剂,考察了Pd负载量、ZSM-5分子筛的硅铝比和Pd/Pt质量比对整体式催化剂的丙烷催化燃烧性能的影响,并用超声波振荡、SEM、XRD、H2-TPR和C3H8-TPD等手段对整体式催化剂进行了表征。当球磨时间为60 min,分子筛浆料固含量为38%时,整体式催化剂的涂层上载量可达到178 g?L-1,涂层脱落率低于0.5%。Pd2Pt3-ZSM-5/Cordierite整体式催化剂(贵金属总负载量为1.2 g?L-1)对于丙烷的催化燃烧具有较好的催化活性(T50=259℃,T90=323℃)和稳定性,具有良好的工业应用前景,其中较低的ZSM-5分子筛硅铝比以及Pd和Pt之间的相互作用增加了对丙烷的吸附能力和表面活性氧物种的数量,从而提高了整体式催化剂的催化活性。 相似文献