Microporosity and Catalytic Activity for Hydrodesulfurization of Pharmacosiderite MoPO Synthesized at a Moderate Temperature.

Pharmacosiderite MoPO (Pharma-MoPO) consists of [MoO] cubane unit and [PO] tetrahedral to form an open framework with a microporous structure similar to that of LTA-type zeolite. Although attractive applications are expected due to its microporous structure and redox-active components, its physicochemical properties have been poorly investigated due to the specificity of its synthesis, which requires a high hydrothermal synthesis temperature of 360 °C. In this study, we succeeded in synthesizing Pharma-MoPO by hydrothermal synthesis at 230 °C, which can be applied using a commercially available autoclave by changing the metal source.

Molybdenum Oxide Constructed by {MoO} Pentagonal Unit Assembly and Its Redox Properties.

Molybdenum oxides are widely used in various fields due to their electronic and structural characteristics. These materials can generate lattice oxygen defects by reduction treatments, which sometimes play central roles in various applications. However, little has been understood about their properties since it is difficult to increase the amount of lattice oxygen defects due to the crystal structure changes in most cases.

Oxidation Catalysis over Solid-State Keggin-Type Phosphomolybdic Acid with Oxygen Defects.

Keggin-type phosphomolybdic acid (PMoO), treated with pyridine (Py), forms a crystalline material (PyPMo-) following heat treatment under an inert gas flow at ∼420 °C. Although this material is known to have attractive catalytic properties for gas-phase oxidation, the origin of this catalytic activity requires clarification. In this study, we investigated the crystal structure of PyPMo-.

Synthesis of High Dimensionally Structured Mo-Fe Mixed Metal Oxide and Its Catalytic Activity for Selective Oxidation of Methanol.

High-dimensionally structured Mo-Fe oxide (HDS-MoFeO) was synthesized through an assembly of structural units supplied from Keplerate-type polyoxometalate, {MoFe}, under an appropriate hydrothermal condition. HDS-MoFeO showed excellent catalytic activity for the selective oxidation of methanol with slightly lower selectivity for formaldehyde than that of a conventional Mo-Fe oxide catalyst.