【摘要】 利用IR，EXAFS13CO同位素交换反应及与NO作用等手段研究了Pt羰基簇合物[Pt3（CO）6]（n＝3，4）在NaY分子筛超笼内的合成机理．在氧化样品Pt2＋／NaY上300－373K的还愿羰基化过程中，首先Pt2＋与CO反应生成PtO（CO）物种（波数σco＝2110cm－1），然后聚集成“Pt3（CO）6”（σco＝2112，1896和1841cm－1），最后生成深绿色的Pt羰基簇合物Pt12（CO）24]2－／NaY（σco＝2080，1824cm-1）．“Pt3（CO）6”的羰基在室温下能迅速地与13CO发生交换，而[Pt3（CO）6]（n＝3，4）的羰基与13CO的同位素交换即使在343K也进行得很慢，室温下，NO能逐步破坏Pt羰基簇合物的层间和层内Pt－Pt键，得到中间物种“Pt3（CO）6”和PtO（CO），同时在气相产生CO2和N2O．而由上述两中间物种出发，300－353K温度下，在CO气氛中的还原羰基化又能可逆地得到原羰基簇合物．更多还原

【Abstract】 The mechanism of the synthesis of platinum carbonyl clusters [Pt3(CO)6](n=3, 4) in cages of NaY was studied by IR, EXAFS 13CO exchange reaction andNo interaction. The results suggest that oaldized Pt species in NaY cages reacts with CO at 300-373K to form PtO(CO) (σco=2110cm-1) which aggregates into "Pt3(CO)6"(σco=2112, 1896 and 1841cm-1) and eventually converts into dark-green carbonyl cluster [Pt12(CO)24]2-. The carbonyl "Pt3(CO)6" can exchange with 13CO very quickly at 298K but the exchange reaction between 13CO and intrazeolite Pt caxbonyl clusters [Pta(CO)6] (n=3, 4) proceeds slowly even at enhanced temperature such as 343K. It is interesting to And that NO breaks successively the intra and inter-trigonal Pt-Pt bonds of the Pt12 carbonyl clusters (even at 298 K ) and the "Pt3(CO)6" formed is further reacted to give PtO(CO) with the formation of N2O and CO2 in the gas phase. [Pt12(CO)24]2-can be reversibly regenerated from the Pt subcarbonyls such as PtO(CO) and "Pt3(CO)6"inside NaY by reacting wich CO at 300-353K.更多还原