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Two K/Mn-MgO supported catalysts were prepared by Fe(CO)5 and Fe(NO3)3 as precursor respectively. The obtained Fe-K/Mn-MgO catalysts were tested for CO hydrogenation to light alkenes and characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectra (XPS), H2 temperature-programmed reduction (H2-TPR), H2 CO and CO2 temperature-programmed desorption (H2, CO/CO2-TPD) and transmission electron microscope (TEM) The results indicated that the catalyst with 10 wt% Fe loading prepared by Fe(CO)5 as precursor showed better performance in syngas to light alkenes than ones obtained from Fe(NO3)3 as precursor, where the CO conversion was 62.50% and the selectivity was 55.95% at 350 ℃, 1.5 MPa and 1000 h^-1, respectively. 相似文献
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在(CH_3)_3NO存在下,PPh_3取代M(CO)_5(M=Fe,Ru,Os)中CO的反应速度遵循二级速度定律,分别与[M(CO)_5]和[(CH_3)_3NO]的一次方成正比,与[PPh_3]无关。反应速度按FeRu>Os的次序约减小4倍。 1 实验方法 典型的动力学实验中,将(CH_3)_3NO的C_2H_5OH溶液和PPh_3的己烷溶液分别用注射器加到体积合适的烧瓶中,再注入Fe(CO)_5并迅速震荡烧瓶,再取出一部分反应液立即注入充N_2 相似文献
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以铝柱撑蒙脱石为载体,用沉积沉淀法在其表面负载金属Au后制备了Au负载铝柱撑蒙脱石高效负载型催化剂。以XRD,TEM,XPS等手段对催化剂的结构进行了表征,并研究了铝柱撑蒙脱石负载前后CO催化氧化活性的变化规律。结果证明,Au是以高度分散的状态均匀分布在铝柱撑蒙脱石载体表面,且以Au0和Au3+的混合价态形式存在。CO催化氧化活性表征结果表明,负载后催化剂的催化活性有了显著提高,且其催化活性随着负载量的增加而不断增强,但当负载量增大到一定程度后,其催化活性不再继续增加,且有所下降。 相似文献
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常温常湿CO氧化催化剂Au/Fe2O3的制备与稳定性研究 总被引:4,自引:2,他引:4
研究了不同方法制备的Au/Fe2O3催人上常温常湿条件下CO的氧化性能。结果表明,加料顺序、焙烧温度、沉淀剂种类、金含量等因素对催化剂的稳定性均有较大影响,其中以K2CO3或Na2CO3为沉淀剂,金含量3%,焙烧温度250~350℃制得的催化剂具有较好的稳定性和抗水性,于25℃连续加篱水蒸气反应430h可保持CO完全转化,XRD结果表明,催化剂的稳定性与单质金及α-Fe2O3的粒径成反比,并与反应 相似文献
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在温和水热体系中合成出单相水合石榴石Sr3Fe2(OH)12,产物在573K左右经历快速的与Sr最近邻的OH断裂与分解过程,在空气或氧气中焙烧出现从Fe(Ⅲ)到Fe(Ⅳ)的氧化,骨架Fe离子价态变化直接决定分解过程的及产物的结构类型,采用Moessbauer谱联用XPS法测出Sr-Fe水合石榴石晶格中存在2种八面体Fe(OH)6。 相似文献
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担载Fe2(CO)9络合物及其分散型Fe催化剂的CO吸脱附和催化作用 总被引:1,自引:0,他引:1
担载于Al2O3和ZrO2上的Fe(CO)9络合物的羰基在真空中极易脱附,在Ar或H2中250℃左右也可完全脱羰而成分散型催化剂。以ZrO2为载体者在Ar中低温下易发生表面岐化反应而生成CO2,高温下生成少量CH4。吸附于分散型催化剂上的CO在Ar或H2中均易发生岐化反应,以ZrO2为载体者在H2中发生加氢反应而生成CH4,在CO加氢中其反应物除了大量CO2外还有少量CH物。原位FT-IR谱表明以 相似文献
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利用SHIP-IN-BOTTLE技术在NaY分子筛中合成Ru_8(CO)_(12)原子簇肖丰收,徐如人,何亚男,丁红,张艳秋(吉林大学化学系,长春,130023)关键词原子簇,Ru_3(CO)_12,NaY分子筛,钌,羰基在多相催化研究中,金属羰基簇合物... 相似文献
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由HRuCo_3(CO)_(12)制备的催化剂在CO加氢反应中,若在初始阶段或温度较低的条件下,含氧产物大部分是甲醇;若增加反应时间或提高反应温度,C_2含氧化合物则是主要产物。原位红外光谱揭示了甲酰基和乙酰基分别是形成甲醇和C_2含氧化合物的中间体,而且乙酰基来自甲酰基与甲基的相互工作用。 相似文献
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担载于Al_2O_3上的NaRuCO_3(CO)_(12)络合物在IR光谱上出现类似于Ru(CO)_2O_2络合物特征带的羰基带,在300~400℃左右变强,在CO中尤为明显。在以ZrO_2为载体时出现与原来络合物相近的弱羰基带。当CO吸附于以Al_2O_3为载体的脱羰基催化剂上时,发现在氧化态催化剂上也出现了与担载络合物相似的吸收带,在还原态催化剂上只出现线式带。吸附于以ZrO_2为载体的脱羰基催化剂上的CO不出现CO的IR吸收带,在He中亦无TPD脱附物,在H_2中却可发生加氢反应生成CH_4。从Na~+和ZrO_2协同效应角度,探讨了CO在上述两种分散型催化剂上吸脱附行为不同的原因。 相似文献
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JingYangJIANG QiangMIAO YanHuaWANG ZiLinJIN 《中国化学快报》2004,15(4):394-396
The Ru3(CO)12/PEDPA complex was firstly applied in the CO selective reduction of 4-propylthio-2-nitroaniline.The effects of reaction temperature,the pressure of CO and concentration of catalyst on the reduction were investigated.Under the optimum conditions of T=140℃, Pco=5.0MPa and substrate/catalyst=300(molar ratio),the conversion and selectivity were 70% and 98%,respectively.After simple phase separation,the catalyst could be recycled. 相似文献
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The compound (SiCl3)2Fe(CO)4 was synthesized and structurally characterized by X-ray single-crystal diffraction. It crystallizes in monoclinic, space group P2 1/n with α = 8.287(2), b = 9.829(2), c = 9.042(2) A, β = 96.19(3)°, V= 732.2(3) A^3, C4Cl6FeO4Si2, Mr = 436.77, Z = 2, Dc = 1.981 g/cm^3, F(000) = 424, μ(MoKα) = 2.282 mm^-1, the final R = 0.048 and wR = 0.164 for 1109 observed reflections (I 〉 2σ(I)). The crystal structure of (SiCl3)2Fe(CO)4 reveals that the Si(l)- Fe-Si(l)^a sequence is linear and perpendicular to the Fe(CO)4 cross-shaped plane. 相似文献
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High active and stable gold catalysts supported on crystalline Fe2O3 and CeO2/Fe2O3 were prepared via the deposition-precipitation method. The catalyst with a Au load of 1.0% calcined at 180 °C showed a CO conversion of 100% at -8.9 °C, while Au/CeO2/Fe2O3 converted CO completely at -16.1 °C. Even having been calcined at 500 °C, Au/Fe2O3 still exhibited significant catalytic activity, achieving full conversion of CO at 61.6 °C. The catalyst with a low Au load of 0.5% could convert CO completely at room temperature and kept the activity unchanged for at least 150 h. N2 adsorption-desorption measurements show that the crystalline supports possessed a high specific surface area of about 200 m2/g. Characterizations of X-ray diffraction and transmission electron microscopy indicate that gold species were highly dispersed as nano or sub-nano particles on the supports. Even after the catalyst was calcined at 500 °C, the Au particles remained in a nano-size of about 6―10 nm. X-ray photoelectron spectra reveal that the supported Au existed in metallic state Au0. The modification of Au/Fe2O3 by CeO2 proved to be beneficial to the inhibition of crystallization of Fe2O3 and the stabilization of gold particles in dispersed state, consequently promoting catalytic activity. 相似文献