Catalytic Performance in CO Hydrogenation Over SiO_2-Supported Ru-M (M=Co, Fe,Mo,Ni,Rh,Mn and Cr) Bimetallic Cluster-derived Catalysts

The bimetallic Ru-M (M=Co,Fe,Ni,Mo, Rh,Cr, Mn) catalysts were prepared from SiO_2-supported bimetallic carbonyl clusters, and it was found that the Ru-Co, Ru-Fe and Ru-Mo bimetallic carbonyl cluster-derived catalysts showed higher activity and selectivity for oxygenates such as C_1-C_5 alcohols in CO hydrogenation,in contrast to catalysts prepared from SiO_2-supported homometallic Ru and Co carbonyl clusters. In situ FT-IR studies revealed that the bands at 1584 and 1555 cm~(-1) species were intermediates to produce methanol and higher oxygenates,and at higher temperatures the 1584 cm~(-1) species could react with alkyl to form 1555 cm~(-1) species. By the surface chemical reaction and the IR study of isotopic molecules,it was suggested that 1584 and 1555 cm~(-1) were assigned to surface formyl and acetyl species.     

四钼簇合物Mo_4(μ_3—O)_2O_4Cl_2(OCOC_6H_5)_6和[Mo_4(μ_3—O)_2O_4Cl_2(OCOC_6H_4CH_3)_6]·2C_6H_5Cl的合成、结构、反应机理及光谱性质研究

用MoCl_5和C_ 6H_5COOH(或CH_3C6H_4COOH)在氯苯溶液中反应,得到四钼簇合物Mo_4(μ_3-O)_2O_4Cl_2-(OCOC_6H_5)_6(或[Mo_4(μ_3-O)_2O_4Cl_2(OCOC_6H_4CH_3)_6]·2C_6H_5Cl)晶体。用X射线单晶衍射法测定了簇合物的晶体结构,运用18电子规则及簇合物的晶体结构数据,得到金属Mo-Mo键键价为1,钼在簇合物中均呈+5价。进行了反应机理的探讨,簇合物中端基氧和桥基氧的存在来自于苯甲酸(对甲基苯甲酸),MoCl_5和C_6H_5COOH(CH_3C_6H_4COOH)作用时,首先生成钼的含氧配合物MoOCl_3,然后生成双核钼配合物Mo_2(μ_2-O)_2O_2Cl_2,进一步形成配合物。红外光谱、激光拉曼光谱和磁化率的测定证明了结构分析的结果。值得注意的是,固体表面光电压谱和固体光声光谱的测定,簇合物Mo_4(μ_3-O)_2O_4Cl_2(OCOC_6H_5)_6的表面光电压谱在～600nm处有一光致电荷分离谱带。     

四钼簇合物Mo4(μ3-O)2O4Cl2(OCOC6H5)6和[Mo4(μ3-O)2O4Cl2(OCOC6H4CH3)6]·2C 总被引：2，自引：0，他引：2

姜燕  樊玉国  孙春亭  李铁津 《无机化学学报》1990,6(3):261-266