2007 Fiscal Year Final Research Report Summary
Catalysis of Gold Clusters Fixed in the Nanospace of Metal Complexes
| Project/Area Number |
16074218
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| Research Category |
Grant-in-Aid for Scientific Research on Priority Areas
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| Allocation Type | Single-year Grants |
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| Review Section |
Science and Engineering
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| Research Institution | Tokyo Metropolitan University (2005-2007)
National Institute of Advanced Industrial Science and Technology (2004) |
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Principal Investigator |
MASATAKE Haruta Tokyo Metropolitan University, Graduate School of Urban Environmental Sciences, Professor (10357824)
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| Co-Investigator(Kenkyū-buntansha) |
TAKEI Takashi Tokyo Metropolitan University, Graduate School of Urban Environmental Sciences, Associate Professor (00197253)
ISHIDA Tamamo Tokyo Metropolitan University, Graduate School of Urban Environmental Sciences, Assistant Professor (90444942)
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| Project Period (FY) |
2004 – 2007
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| Keywords | Environmental chemical processes / Nanomaterials / Environmental materials |
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| Research Abstract |
Gold in bulk was regarded as being inert, however, it exhibits markedly high catalytic activity when deposited as nanoparticles on base transition metal oxides. Since it is expected that dramatic changes due to quantum size effect may happen when gold is minimized down to clusters with diameters below 2um, we have attempted to fix gold clusters inside the nano-space of porous cordination polymers(PCPs). In the present work, we have deposited gold clusters on a variety of PCPs such as copper-complex porous polymer, CPL-2([Cu_2(pzdc)_2(bpy)]_n(pzdc=pyridine-2,3-dicarboxylate, bpy=4,4'-bipyridine) which has one dimensional nano-spaces with a size of 0.6x0.8 nm by mixing with an organic gold complex, dimethy gold acetylacetonate, in a ball mill. The solid ground mixture was reduced in a stream of 10vol%H_2 in N_2 at 120℃. This solid gring method is really new but the most effective and simplest technique to deposit gold clusters on a variety of materials including polymers and carbons. The
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mean diameter of gold clusters ranges from 5 to 1.5 nm depending on the elements of metal complexes in PCPs. It is surprising that these small gold clusters deposited on polymer materials were not active at all for the gas phase oxidation of CO and H_2. This result supports our hypothesis that oxygen molecule is activated at the periphery around gold clusters or nanoparticles and therefore metal oxides support play an important role in the catalysis. In contrast to gas phase reactions, in water and organic solvents the polymer supported gold clusters exhibited distiquishable catalytic activity for glucose and alcohol oxidation with molecular oxygen, indicating that oxidation takes place mainy on the gold surfaces. It was also revealed that by choosing the kind of polymer supports product selectivity is tunable. In conclusion, gold was directly deposited on porous cordination polymers as clusters for the first time in the world and they showed a great potential as a heterogeneous catalsyt that can lead to green sustainable chemsitry. Less
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