Huang Jier, Blakemore James D, Fazi Diego, Kokhan Oleksandr, Schley Nathan D, Crabtree Robert H, Brudvig Gary W, Tiede David M
Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Phys Chem Chem Phys. 2014 Feb 7;16(5):1814-9. doi: 10.1039/c3cp54878c.
The domain structure of an amorphous, "blue layer" iridium-oxide water-oxidation catalyst film (BL) electrodeposited from the soluble precursor complex, [Cp*Ir(H2O)3]SO4, was characterized by X-ray pair distribution function (PDF) analysis. The results show that the experimental PDF can be fit remarkably well using a single Ir5O22 cluster extracted from the rutile lattice. The model includes distortions that indicate the presence of Ir(μ-O)3Ir or distorted Ir(μ-O)2Ir substructures, and hence deviations from a rutile structure. The five Ir atom cluster is suggested to represent the population-averaged distribution of metal-oxo clusters in the film. BL is found to be distinguished from other amorphous film water-oxidation catalysts because of the remarkably small domain size and homogeneity. As such, the blue layer catalyst provides a model for investigating ligand-determined metal-oxide cluster assembly and catalyst mechanism.
通过X射线对分布函数（PDF）分析对由可溶性前体配合物[Cp*Ir(H₂O)₃]SO₄电沉积得到的非晶态“蓝色层”氧化铱水氧化催化剂薄膜（BL）的畴结构进行了表征。结果表明，使用从金红石晶格中提取的单个Ir₅O₂₂簇可以很好地拟合实验PDF。该模型包括表明存在Ir(μ-O)₃Ir或扭曲的Ir(μ-O)₂Ir子结构的畸变，因此与金红石结构存在偏差。五个Ir原子簇被认为代表了薄膜中金属-氧簇的总体平均分布。发现BL与其他非晶态薄膜水氧化催化剂不同，因为其畴尺寸非常小且具有均匀性。因此，蓝色层催化剂为研究配体决定的金属氧化物簇组装和催化剂机理提供了一个模型。
