Ammonia decomposition catalyst

Abstract

Disclosed is an ammonia decomposition catalyst which is obtained by subjecting a complex to a heat treatment at a temperature of 360-900 DEG C in a reducing atmosphere, said complex being obtained by coordinating a transition metal to a polymer that is represented by formula (I) and has a molecular weight of 1,000-500,000, and adding activated carbon or a carbon nanotube to the polymer. In the case when a carbon nanotube is added, an alkali metal compound or an alkaline earth metal compound is added to the heat-treated complex. In formula (I), R1 represents H or a hydrocarbon group having 1-10 carbon atoms; R2 and R3 each represents H, a halogen, a nitro group, an acyl group, an ester group, a carboxyl group, a formyl group, a nitrile group, a sulfone group, an aryl group or an alkyl group having 1-15 carbon atoms; X and Y each represents H or OH; Z represents CH or N; R4 and R5 each represents H, OH, an ether group, an amino group, an aryl group or an alkyl group having 1-15 carbon atoms; x represents a real number between 1 and 2; y represents a real number between 1 and 3; and n represents a real number between 2 and 120. The ammonia decomposition catalyst is capable of increasing the amount of transition metal loaded thereon without lowering the dispersion of the transition metal, and is capable of reducing the use amount of catalyst necessary for obtaining desired activity.

Description

technical field [0001] The present invention relates to an ammonia decomposition method or an ammonia decomposition catalyst carrying a transition metal used in producing hydrogen from ammonia. Background technique [0002] Until now, the catalyst of carrying ruthenium as active metal in carrier is to use basic oxides such as magnesia or active carbon as carrier, utilize impregnated carrying method etc. to carry the catalyst of ruthenium in described carrier (see patent Document 1 and Patent Document 2). In the catalyst with the above structure, since the interaction between ruthenium and the support is not so strong, ruthenium cannot be well immobilized on the support. Therefore, in the reduction step performed after the ruthenium is carried on the carrier, aggregation of ruthenium tends to occur, and the dispersibility decreases. Generally, since the catalytic reaction of the supported metal catalyst occurs on the surface of the supported metal particles, when the suppor...

AI Technical Summary

Problems solved by technology

In the catalyst with the above structure, since the interaction between ruthenium and the support is not so strong, ruthenium cannot be immobilized on the support well.

Therefore, in the reduction process performed after the ruthenium is carried on the carrier, the ruthenium is likely to aggregate and the dispersibility decreases.

Usually, since the catalytic reaction of the supported metal catalyst occurs on the surface of the supported metal particles, when the supported metal particles aggregate and the particle size becomes larger, the surface area of ​​the supported metal decreases, thereby reducing the activity.

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