Reactivity of iron carbonyl complexes in a hydrated sodium-Y zeolite matrix and catalysis of the resulting hydride anion HFe3(CO)11- for water-gas-shift reaction
Reactivity of iron carbonyl complexes in a hydrated sodium-Y zeolite matrix and catalysis of the resulting hydride anion HFe3(CO)11- for water-gas-shift reaction
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DOI：
10.1021/j100412a069
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发表时间：
1986-10
期刊：
影响因子：
--
通讯作者：
M. Iwamoto;Shinichiro Nakamura;Hideto Kusano;S. Kagawa
中科院分区：
文献类型：
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作者：
M. Iwamoto;Shinichiro Nakamura;Hideto Kusano;S. Kagawa
羰基铁 Fe(CO)/sub 5/、Fe/sub 2/(CO)/sub 9/ 和 Fe/sub 3/(CO)/sub 12/ 已被引入水合 Na-Y 沸石中。 Fe(CO)/sub 5/仅微弱地吸附在沸石上。 Fe/sub 2/(CO)/sub 9/ 和 Fe/sub 3/(CO)/sub 12/ 在水合沸石笼中发生反应，产生氢化物阴离子 HFe/sub 3/(CO)/sub 11//sup -/，其特征在于 2044、1987、1950 和 1645 cm/sup -1/ 处的红外吸收带，UV-vis 540 nm 处的光谱，以及 气相分析。桥接羰基的吸收带的红移表明桥接羰基与沸石基质中的Al/sup 3 +/ 离子的离子相互作用。在脱水的 Na-Y 沸石中没有观察到阴离子物质的形成，这表明水或表面羟基在反应中的重要性。通过ESR技术研究了从二核或三核羰基铁到氢化物阴离子的反应过程。检测到中间体 Fe/sub 2/(CO)/sub 8//sup -/、Fe(CO)/sub 4//sup -/ 和 Fe/sub 3/(CO)/sub 11//sup -/ 物质，并提出了反应方案。所得 HFe/sub 3/(CO)/sub 11//sup -/ 在真空或 CO 气氛中在 413 K 或更低温度下均稳定。高于这个温度，它会逐渐分解。检查了 HFe/sub 3/(CO)/sub 11//sup -/ 物质在 333-453 K 和大气压下的水煤气变换反应的催化活性。活性非常高，与高压均相中报道的活性相当。动力学和光谱研究表明 HFe/sub 3/(CO)/sub 11//sup -/ 和 H/sub 2/O 之间的反应将是决定速率的。 « less
Iron carbonyls Fe(CO)/sub 5/, Fe/sub 2/(CO)/sub 9/, and Fe/sub 3/(CO)/sub 12/ have been introduced into a hydrated Na-Y zeolite. Fe(CO)/sub 5/ was only weakly adsorbed on the zeolite. Fe/sub 2/(CO)/sub 9/ and Fe/sub 3/(CO)/sub 12/ were reactive in the hydrated zeolite cages to yield a hydride anion species HFe/sub 3/(CO)/sub 11//sup -/ which was characterized by IR absorption bands at 2044, 1987, 1950, and 1645 cm/sup -1/, UV-vis spectrum at 540 nm, and gas-phase analyses. The red shift of absorption band of the bridging carbonyl indicated ionic interaction of a bridging carbonyl with an Al/sup 3 +/ ion in the zeolite matrix. The formation of the anion species was not observed in a dehydrated Na-Y zeolite, indicating the importance of water or a surface hydroxyl group n the reaction. The reaction course from di- or trinuclear iron carbonyl to the hydride anion has been studied by an ESR technique. Fe/sub 2/(CO)/sub 8//sup -/, Fe(CO)/sub 4//sup -/, and Fe/sub 3/(CO)/sub 11//sup -/ species were detected as intermediates, and reaction schemes have been proposed. The resulting HFe/sub 3/(CO)/sub 11//sup -/ was stable at or below 413 K both in a vacuum or in a CO atmosphere. Above this temperature it was graduallymore » decomposed. Catalytic activity of the HFe/sub 3/(CO)/sub 11//sup -/ species was examined for water-gas-shift reaction at 333-453 K and atmospheric pressure. The activity was very high and comparable to that reported in the homogeneous phase at high pressure. Kinetics and spectroscopic studies indicated that the reaction between HFe/sub 3/(CO)/sub 11//sup -/ and H/sub 2/O would be rate-determining.« less