Carbon-intersticed metallic palladium, palladium catalyst and method for preparation thereof, and method for producing alpha,beta-unsaturated carboxylic acid

14:

• A carbon-insertion-type palladium metal wherein an amount of inserted carbon is 0.16 mol or more with respect to 1.0 mol of a palladium metal.

15:

• A carbon-insertion-type palladium metal wherein a crystal face distance of a (111) face of a palladium metal calculated from a diffraction angle measured by an X-ray diffraction analysis is 2.270 Å or more.

16:

• A palladium catalyst comprising the carbon-insertion-type palladium metal according to claim 14.

17:

• The palladium catalyst according to claim 16, wherein said palladium catalyst is utilized for the preparation of an α,β-unsaturated carboxylic acid.

18:

• A palladium catalyst comprising the carbon-insertion-type palladium metal according to claim 15.

19:

• The palladium catalyst according to claim 18, wherein said palladium catalyst is utilized for the preparation of an α,β-unsaturated carboxylic acid.

20:

• A method for the preparation of a carbon-insertion-type palladium metal, comprising a step of reducing palladium in a palladium compound in a palladium compound solution in which the palladium compound having a chlorine content of 0 to 300 ppm is dissolved in a solvent.

21:

• The method for the preparation of a carbon-insertion-type palladium metal according to claim 20, wherein the step is performed at −5 to 150° C.

22:

• The method for the preparation of a carbon-insertion-type palladium metal according to claim 20, wherein the solvent is an organic solvent or a mixed solvent of water and an organic solvent.

23:

• The method for the preparation of a carbon-insertion-type palladium metal according to claim 22, wherein the organic solvent contains at least one selected from the group consisting of carboxylic acids, ketones, and alcohols.

24:

• The method for the preparation of a carbon-insertion-type palladium metal according to claim 20, wherein the reduction step is performed by a reducing agent.

25:

• The method for the preparation of a carbon-insertion-type palladium metal according to claim 24, wherein the reducing agent is an olefin having 2 to 6 carbon atoms.

26:

• The method for the preparation of a carbon-insertion-type palladium metal according to claim 20, wherein an amount of inserted carbon is 0.16 mol or more with respect to 1.0 mol of a palladium metal.

27:

• The method for the preparation of a carbon-insertion-type palladium metal according to claim 20, wherein a crystal face distance of a (111) face of a palladium metal calculated from a diffraction angle measured by an X-ray diffraction analysis is 2.270 Å or more.

28:

• A method for the preparation of a palladium catalyst comprising preparing a carbon-insertion-type palladium metal according to the method of claim 20.

29:

• A method for the preparation of a palladium catalyst comprising preparing a carbon-insertion-type palladium metal according to the method of claim 26.

30:

• A method for the preparation of a palladium catalyst comprising preparing a carbon-insertion-type palladium metal according to the method of claim 27.

31:

• A method for the preparation of an α,β-unsaturated carboxylic acid in which an oxidation reaction of an olefin or an α,β-unsaturated aldehyde with molecular oxygen in a liquid phase to prepare the α,β-unsaturated carboxylic acid is performed in the presence of the palladium catalyst according to claim 17.

32:

• A method for the preparation of an α,β-unsaturated carboxylic acid in which an oxidation reaction of an olefin or an α,β-unsaturated aldehyde with molecular oxygen in a liquid phase to prepare the α,β-unsaturated carboxylic acid is performed in the presence of the palladium catalyst according to claim 19.