Porous structure for exhaust gas purification catalyst, exhaust gas purification catalyst using porous structure, and exhaust gas purification method

An exhaust gas purification catalyst comprising a substrate and a catalyst layer on the substrate,

• the catalyst layer comprising an oxygen storage component and an inorganic porous solid,
• the exhaust gas purification catalyst having a pore volume distribution such that a ratio of a pore volume of pores with a diameter of from 15 nm to less than 25 nm to a pore volume of pores with a diameter of from 5 nm to less than 15 nm is 1.4 to 2.5 as measured with a mercury porosimeter,
• the pore volume distribution having at least one peak top in a pore diameter range of from 15 nm to less than 25 nm, and
• the pore volume distribution having a ratio of a pore volume of pores with a diameter of from 5 nm to less than 15 nm to a pore volume of pores with a diameter of 5 to 200 nm is 15% to 35%, and a ratio of a pore volume of pores with a diameter of from 15 nm to less than 25 nm to a pore volume of pores with a diameter of 5 to 200 nm is 25% to 55%.