Method for producing catalyst fibrous structure

A catalyst fibrous structure having a catalyst metal carried on a fibrous structure, which satisfies all the following requirements (a), (b) and (c):

• (a) a Log differential micropore volume distribution curve thereof obtained by measurement using a mercury intrusion technique has its maximum peak at a micropore diameter in the range of from 0.1 μm to 100 μm,
• (b) a Log differential micropore volume at the peak is 0.5 mL/g or more, and
• (c) an amount of a catalyst metal compound and a binder carried per unit volume is from 0.05 g/mL to 0.6 g/mL,
• wherein the fibrous structure is a fiber sheet, and
• wherein the fibrous structure comprises at least one type selected from silica fibers, alumina fibers, glass fibers and carbon fibers, or mixed fibers of a combination of two or more types selected from silica fibers, alumina fibers, glass fibers and carbon fibers.

A production method for a catalyst fibrous structure comprising the following steps (1) to (5):

• (1) a step of mixing a catalyst metal compound or a catalyst precursor, and an inorganic binder and a solvent;
• (2) a step of grinding the obtained mixture to provide a coating material of the catalyst metal compound or the catalyst precursor having a median particle diameter of 2 μm or less, a viscosity of from 30 mPa·s to 200 mPa·s and a solid content of from 20% by mass to 40% by mass;
• (3) a step of impregnating a fibrous structure with the obtained coating material of the catalyst metal compound or the catalyst precursor to fill up voids of the fibrous structure with the coating material of the catalyst metal compound or the catalyst precursor;
• (4) a step of heating and drying the obtained fibrous structure filled up with the coating material of the catalyst metal compound or the catalyst precursor, at a temperature not lower than the boiling point of the solvent;
• and
• (5) a step of heating and calcination the dried fibrous structure having the catalyst metal compound or the catalyst precursor adhered thereto at a temperature not lower than the dehydration temperature of the inorganic binder to provide a catalyst fibrous structure,
• wherein the fibrous structure is a fiber sheet comprising at least one type selected from metal oxide fibers, glass fibers and carbon fibers.