CATALYST FOR PURIFYING EXHAUST GAS

• Main Authors: ARAKAWA TAKUTO, FUJITA NOZOMI, YAMASHITA YOSHINORI, TANAKA ERIKO, AONO NORIHIKO
• Format: Patent
• Language: English; Japanese
• Published: 08.11.2018
• Subjects: BLASTING; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; STEAM ENGINES; THEIR RELEVANT APPARATUS; TRANSPORTING; WEAPONS

PROBLEM TO BE SOLVED: To provide a catalyst for purifying exhaust gas at a low cost, capable of suitably suppressing phosphorus poisoning of a metal catalyst, and retaining sufficient exhaust gas-purifying property for a long term.SOLUTION: A catalyst 10 for purifying exhaust gas includes: a base material 11 in which a plurality of cells 15 are partitioned by partition walls 16; a catalyst layer 30 formed on a partition wall 16 surface of the base material 11; and a phosphorous collection layer 20 provided on the catalyst layer 30. The phosphorous collection layer 20 has a phosphorous collection component containing at least one selected from La, Fe, Zr, Ce, Ti, Sr, Ca, Mg, Pr and Y. When the phosphorous collection layer is 100% in an electron microscope image of the cross section of the phosphorous collection layer 20, large pores whose equivalent circle diameter is larger than 5 μm occupy 45% or more.SELECTED DRAWING: Figure 3 【課題】金属触媒のリン被毒を好適に抑制し、十分な排ガス浄化性能を長期間に亘って維持することができる排ガス浄化用触媒を安価に提供する。【解決手段】ここで開示される排ガス浄化用触媒１０は、複数のセル１５が隔壁１６によって仕切られた基材１１と、基材１１の隔壁１６表面に形成された触媒層３０と、触媒層３０上に設けられたリン捕集層２０とを備えている。そして、かかるリン捕集層２０は、Ｌａ、Ｆｅ、Ｚｒ、Ｃｅ、Ｔｉ、Ｓｒ、Ｃａ、Ｍｇ、Ｐｒ、Ｙのうち少なくとも一つを含むリン捕集成分を有しており、リン捕集層２０の断面の電子顕微鏡観察画像において、リン捕集層を１００％としたときに、円相当径が５μｍよりも大きな大細孔が４５％以上を占めている。【選択図】図３