Synthesis and Application of Nanoporous Photocatalysts

光催化剂通过水裂解和甲醇分解将能量转化为清洁的氢能而备受关注。过去十年光催化的显著进展仅限于紫外光，而不是更有用的可见光区域。因此，开发可见光光催化剂已成为当今光催化研究的重要课题之一。微孔有机-无机杂化配位聚合物因其分子吸附、离子交换和催化活性而受到广泛关注。在所有这些高效多孔材料中，我们研究了过渡金属羧酸盐配位聚合物的合成，例如铜、钼和钌的二羧酸盐，它们能够阻挡大量的各种气体。最近，我们还成功地合成了含有金属卟啉的过渡金属羧酸盐微孔配合物，该配合物具有高的气体遮挡性能和高的氧化和加氢反应催化活性。在这项研究中，我们证明了Fe[MTCPP] (M=Cu^<2+>,Fe^<3+>;H_2TCPP = 4,4 ‘,4″，4″’ -（21H， 23h -卟啉-5,10,15,20-四基苯甲酸四酯）配合物在可见光照射下催化甲醇的光分解活性。气态甲醇的光分解是在传统的密闭气体循环系统中进行的。气相色谱（TCD，不锈钢柱，Porapak Q和5A分子筛，FID毛细管柱，DB-WAX）分析产物为氢、甲醛和水。Fe[FeTCPP]在可见光区表现出五条吸附带。它们显示了5.6和6.2的微孔Å。155h后，它们的周转率为0.25，远高于Fe[CuTCPP]和Fe[PdTCPP]。

Photocatalysts have attracted much attention because they convert energy into clean hydrogen energy by water splitting and decomposition of methanol. The remarkable progress of the past decade in photocatalysis has been limited to ultraviolet light instead of the more useful visible-light region. The development of visible-light photocatalysts, therefore, has become one of the most important topics in photocatalysis research today. Microporous organic-inorganic hybrid coordination polymers have attracted much attention because of their molecular adsorption, ion-exchange, and catalytic activities. Of all these efficient porous materials, we have studied the synthesis of transition-metal carboxylate coordination polymers, e.g., dicarboxylates of copper, molybdenum, and ruthenium, which are capable of occluding large amounts of various gases. 'Very recently, we have also succeeded to synthesize microporous transition-metal carboxylate complexes containing metalloporphyrins, which showed high gas occlusion properties and high catalytic activities for oxidation and hydrogenation reaction.In this study, we demonstrated the catalytic activities of Fe[MTCPP] (M=Cu^<2+>,Fe^<3+>;H_2TCPP = 4,4′,4″,4″′-(21H,23H-porphine-5,10,15,20-tetrayl)tetrakis benzoate) complexes for photo-decomposition of methanol under visible-light irradiation. The photo-decomposition of gaseous methanol was carried in a conventional closed gas circulation system. The products were hydrogen, formaldehyde and water, which were analyzed by GC (TCD, Stainless column, Porapak Q and Molecular sieve 5A, FID Capillary column, DB-WAX).Fe[FeTCPP] showed five adsorption bands in visible-light region. They showed the micropores of 5.6 and 6.2 Å. They showed ca.25 turnover numbers after 155h, which was much higher than that of Fe[CuTCPP] and Fe[PdTCPP].