Patent ID: 7939461

Claim:
A catalyst for decomposition of formic acid comprising a dinuclear metal complex represented by a formula (1) below, a tautomer or stereoisomer thereof, or any of their salts, where M 1 and M 2 are transition metals and may be the same or different; Ar is a ligand having aromaticity and may be unsubstituted or substituted by one or more substituents; R 1 to R 5 are each independently a hydrogen atom, an alkyl group, a phenyl group, or a cyclopentadienyl group; R 12 to R 27 are each independently a hydrogen atom, an alkyl group, a phenyl group, a nitro group, a halogen group, a sulfonic acid group (sulfo group), an amino group, a carboxylic acid group (carboxy group), a hydroxy group, or an alkoxy group, or R 15 and R 16 may together form a —CH═CH—, that is, R 15 and R 16 may, together with a bipyridine ring to which R 15 and R 16 are bonded, form a phenanthroline ring, where Hs in the —CH═CH— may be each independently replaced by an alkyl group, a phenyl group, a nitro group, a halogen group, a sulfonic acid group (sulfo group), an amino group, a carboxylic acid group (carboxy group), a hydroxy group, or an alkoxy group, and R 23 and R 24 may together form a —CH═CH—, that is, R 23 and R 24 may, together with a bipyridine ring to which R 23 and R 24 are bonded, form a phenanthroline ring, where Hs in the —CH═CH— may be each independently replaced by an alkyl group, a phenyl group, a nitro group, a halogen group, a sulfonic acid group (sulfo group), an amino group, a carboxylic acid group (carboxy group), a hydroxy group, or an alkoxy group; L is an arbitrary ligand or is absent; and m is a positive integer, 0, or a negative integer.