Dynamic Spectrochemical studies on Metal Clusters in Confined Microspace

有限微空间金属团簇的动态光谱化学研究

• 批准号: 06403004
• 负责人: ICHIKAWA Masaru
• 金额: $ 20.99万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06403004/
• 关键词: Cofined Metal Clusters; Dynamic spectrochemistry; Spatial control

We have insutaled a time-resolved FTIR (Bio-Rad, FTS60A/896) spectroscopic system coupled with MOPO and Yag Laser-triger with a 5 mus-ms time-resolution. We have applied this system to study the dynamic behavior of metal carbonyl clusters such as [Pt_9(CO)_<18>]^<2-> and [Pt_<12>(CO)_<24>]^<2-> encapsulated in the confined micropores of NaY zeolite (13 * diamter) after a laser-pulse excitation under the CO+H_2O and NO+CO reaction atmospheres at 300-327K.Additionally, we have studied a in-situ observation of surface species formed in a photo-desorption of CO on Rh/SiO_2 and CO+H_2 reaction on Ni/SiO_2 by the ms resolution. We extended works to synthesize Pt_9-Pt_<15> and Ru_6 carbonyl cluster complexes and bimetallic RhIr, RuCo and RuFe bimetal clusters inside micropores of NaY and ordered mesopores of FSM-16 by the "ship-in-bottle" technique, which have been characterized by EXAFS/TEM,FTIR,and UV-VIS,which have been investigated on their reversible transformation of cluster frameworks … More in micropores. Other topics of research project are briefly summarized as follows.(1) Pt_<12> and Pt_9 carbonyl cluster anions synthesized NaY zeolite promote a CO+H_2O reaction to produce CO_2fH_2 substantially unders the iluimation of Hg lamp. The time-resolved IR study suggested that the Pt_<12> carbonyl in NaY supercage are effectively excited and transformed, resulting in the thermal activation of the cluster-solvated water molecules in 70 ms uncder the pulse-irradiation of the 680 nm laser light.(2) The time-resolved FTIR studies have been conducted to reveal the dynamic behaviors of [CHx] and [OH] species formed Rh/SiO_2 and Ni/SiO_2 in CO+H_2 reaction.(3) The rapid-scan FTIR/EXAFS studies showed the NO reduction with CO to form N_2 (N_2O) proceeded catalytically on [Pt_<12>(CO)_<24>]^<2->/NaY via the reversible tranformation of their cluster frameworks (Pt_<12>(CO)_<24>]^<2->/NaY<==>["Pt_3(CO)_6"+Pt(CO)]/NaY.(4) By the rapid-scan FTIR/EXAFS studies it was di scussed on the mechanism of NO decomposition towards N_2(N_2O)+O_2 on Au(1)NaY at 300-373K,and selective reduction of NO with H_2 to give N_2+H_2O without formation of NH_3 and an effective oxygen promotion of the reaction due to the specific formation of "No_2(N_2O_4)" on the catalyst surface. Less

我们研制了一套时间分辨FTIR（Bio-Rad，FTS 60 A/896）光谱系统，该系统与MOPO和Yag激光触发器联用，时间分辨率为5 μ s-ms。我们利用该系统研究了<18><2-><12><24><2->在300- 327 K的CO+H_2O和NO+CO反应气氛下，NaY沸石（13 * 直径）微孔中金属羰基簇合物[Pt_9（CO）_ ]^和[Pt_（CO）_ ]^在激光脉冲激发下的动力学行为，并对CO在Rh/SiO_2和CO+H_2在Ni/SiO_2上的光脱附反应中形成的表面物种进行了原位观察。我们利用<15>“瓶中船”技术在NaY微孔和FSM-16有序介孔中合成了Pt_9-Pt_6和Ru_6羰基簇合物和Pt_9-RhIr、RuCo和RuFe簇合物，并用EXAFS/TEM、FTIR和UV-VIS对其进行了表征，并研究了簇合物骨架的可逆转变 ...更多信息 在微孔中。研究项目的其他主题简述如下。(1)NaY<12>分子筛合成的Pt_2和Pt_9羰基簇阴离子在汞灯照射下促进CO+H_2O反应生成CO_2fH_2。时间分辨红外光谱研究表明，在<12>680 nm激光脉冲辐照下，NaY超笼中的Pt_羰基被有效激发和转化，导致团簇溶剂化水分子在70 ms内发生热活化。(2)利用时间分辨红外光谱研究了Rh/SiO2和Ni/SiO2在CO+ H2反应中形成的[CHx]和[OH]物种的动力学行为。(3)快速扫描FTIR/EXAFS研究表明，[Pt_（CO）_ ]^ /NaY催化剂上CO还原NO生成N_2（N_2O）的反应<12><24>是<2->通过簇合物骨架（Pt_<12>（CO）_<24>]^<2->/NaY&lt;=&gt;[“Pt_3（CO）_6”+Pt（CO）]/NaY的可逆转化进行的。(4)用快速扫描FTIR/EXAFS研究了300- 373 K时NO在Au（1）NaY上分解为N_2（N_2O）+O_2的机理，以及NO与H_2的选择性还原为N_2+H_2O而不生成NH_3和由于在催化剂表面上特异性生成“NO_2（N_2O_4）”而有效的氧促进反应的机理。少

项目成果

T. Shido: "Rh_4 Carbonyl Clusters Coordinated with Tris-(hydroxymethyl) Phosphine Grafted on SiO_2 Surface and Structural Controlling of Active Site in Gas-phase olefin Hydroformylation Reaction." J. Catal.,. 157. 436-449 (1995)

T. Shido：“Rh_4 羰基簇与 SiO_2 表面接枝的三（羟甲基）膦配位以及气相烯烃加氢甲酰化反应中活性位点的结构控制”。

M.Ichikawa, Wei Pan, Y.Imada, M.Yamaguchi, K.Isobe and T.Shido: "Surface-Graphted Metal Oxide Clusters and Metal Carbonyl Clusters in Zeolite Micropores ; XAFS/FTIR/TPD Characterization and Catalytic Behaviors" J.Mol.Catal., A. 107. 23-38 (1996)

M.Ichikawa、Wei Pan、Y.Imada、M.Yamaguchi、K.Isobe 和 T.Shido：“沸石微孔中的表面绘制金属氧化物簇和金属羰基簇；XAFS/FTIR/TPD 表征和催化行为”J.

A.-M.Liu: "[Ru_6(CO)_<18>]^<12->in NaX Zeolite Cages:Characterization by EXAFS and FTIR Spectroscopy" J.Chem.Soc.,Chem.Commun.507-508 (1995)

A.-M.Liu：“NaX 沸石笼中的 [Ru_6(CO)_<18>]^<12->：通过 EXAFS 和 FTIR 光谱进行表征”J.Chem.Soc.,Chem.Commun.507-508 (

F.S.Xiao: "Catalytic Performance and Mechanism for Oxyqenated Compound Formation for Ethylene Hydroformylation over Supported Ru-M Bimetallic Cluster-Derived Catalysts" J.Catal.147. 578-593 (1994)

F.S.Xiao：“负载型 Ru-M 双金属簇衍生催化剂上乙烯氢甲酰化氧化化合物形成的催化性能和机理”J.Catal.147。

K. Takahashi: "Molecular Modeling of Supported Metal Catalysts ; SiO_2-Grafted [{η^3-C_4H_7)_2Rh}_2V_4O_<12>] and [(RhCp^*)_4V_6O_<19>] Catalytically Active in Selective Oxidation of Propene towards Acetone" J. C. S., Chem. Commun.,. 1301-1303 (1995)

K. Takahashi：“负载型金属催化剂的分子建模；SiO_2 接枝 [{η^3-C_4H_7)_2Rh}_2V_4O_<12>] 和 [(RhCp^*)_4V_6O_<19>] 在丙烯选择性氧化反应中具有催化活性丙酮”J. C. S., Chem. Commun., 1301-1303 (1995)