Tokyo Institute of Technology

Japan Science and Technology Agency

Tsubame Bhb Co., Ltd.

Institute of Science Tokyo

Yasunori Inoue

Hideo Hosono

Toshiharu Yokoyama

Masaaki Kitano

Michikazu Hara

Yoshitake Toda

Satoru Matsuishi

Fumitaka Hayashi

Kazuhisa Kishida

Shinji Kambara

A molded sintered body containing a mayenite type compound, an inorganic binder sintered material, and a transition metal, wherein a content of the inorganic binder sintered material is 3 to 30 parts by mass with respect to 100 parts by mass of the molded sintered body, and the molded sintered body has at least one pore peak in each of a pore diameter range of 2.5 to 20 nm and a pore diameter range of 20 to 350 nm. A method for producing the molded sintered body, including mixing a precursor of a mayenite type compound and a raw material of an inorganic binder sintered material to prepare a mixture; molding the mixture to prepare a molded body of the mixture; firing the molded body to prepare a fired product; and supporting a transition metal on the fired product to produce a molded sintered body.

Molded sintered body, and method for producing molded sintered body

An ammonia synthesis catalyst having high activity is obtained by having a two-dimensional electride compound having a lamellar crystal structure such as CaN support a transition metal. However, since the two-dimensional electride compound is unstable, the stability of the catalyst is low. In addition, in cases where a two-dimensional electride compound is used as a catalyst support, it is difficult to shape the catalyst depending on reactions since the two-dimensional electride compound has poor processability. A composite which includes a transition metal, a support and a metal amide compound, wherein the support is a metal oxide or a carbonaceous support; and the metal amide compound is a metal amide compound represented by general formula (1).M(NH)&#x2003;&#x2003;(1)(In general formula (1), M represents at least one metal atom selected from the group consisting of Li, Na, K, Be, Mg, Ca, Sr, Ba and Eu; and x represents the valence of M.).

Composite, method for producing composite, ammonia synthesis catalyst, and ammonia synthesis method

A catalyst is provided which is used for continuously synthesizing ammonia using a gas containing hydrogen and nitrogen as a raw material, wherein a transition metal which exhibits catalytic activity is supported by a support, and the support is a two-dimensional electride or a precursor thereof. The two-dimensional electride or the precursor thereof is a metal nitride represented by MxNyHz (M represents one or two or more of Group II metals selected from the group consisting of Mg, Ca, Sr and Ba, and x, y and z are in ranges of 1&#x2264;x&#x2264;11, 1&#x2264;y&#x2264;8, and 0&#x2264;z&#x2264;4 respectively, in which x is an integer, and y and z are not limited to an integer) or MN(M is the same as above), or a metal carbide selected from the group consisting of YC, ScC, GdC, TbC, DyC, HoC and ErC. These catalysts are used for continuously reacting nitrogen with hydrogen, which are raw materials, on the catalyst, wherein the reaction is performed in an ammonia synthesis reaction system under the preferable conditions of a reaction temperature which is equal to or higher than 100&#xb0; C. and equal to or lower than 600&#xb0; C., and a reaction pressure which is equal to or higher than 10 kPa and lower than 20 MPa.

Supported metal catalyst and method of synthesizing ammonia using the same

If a conductive mayenite compound having a large specific surface area is obtained, the usefulness thereof in respective applications is remarkably increased. A conductive mayenite compound powder having a conduction electron density of 10cmor more and a specific surface area of 5 mgor more is produced by: the following steps: (1) forming a precursor powder by subjecting a mixture of a starting material powder and water to a hydrothermal treatment; (2) forming a mayenite compound powder by heating and dehydrating the precursor powder; (3) forming an activated mayenite compound powder by heating the compound powder in an inert gas atmosphere or in a vacuum; and (4) injecting electrons into the mayenite compound through a reduction treatment by mixing the activated mayenite compound powder with a reducing agent.

Method for producing conductive mayenite compound powder having large specific surface area

If a conductive mayenite compound having a large specific surface area is obtained, the usefulness thereof in respective applications is remarkably increased. A conductive mayenite compound powder having a conduction electron density of 10cmor more and a specific surface area of 5 mgor more is produced by: (1) a step for forming a precursor powder by subjecting a mixture of a starting material powder and water to a hydrothermal treatment; (2) a step for forming a mayenite compound powder by heating and dehydrating the precursor powder; (3) a step for forming an activated mayenite compound powder by heating the compound powder in an inert gas atmosphere or in a vacuum; and (4) a step for injecting electrons into the mayenite compound through a reduction treatment by mixing the activated mayenite compound powder with a reducing agent.

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Tokyo, Japan

Yasunori Inoue