Dynamic Spectrochemical studies on Metal Clusters in Confined Microspace

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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