Catalyst for purifying an exhaust gas
US5677254A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 19, 1996 |
| Grant date | Oct 14, 1997 |
| Priority date | — |
| Expiry date | Jun 19, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J29/04
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
This invention relates to a catalyst for purifying an exhaust gas, which has a denitrification property in the lean atmosphere and good durability and is hardly deteriorated even in a high temperature rich atmosphere. The feature thereof consists in a catalyst for purifying an exhaust gas, comprising a crystalline silicate having the specified X-ray diffraction pattern and a chemical composition represented by the following chemical formula in the term of mole ratios of oxides under dehydrated state, EQU (1.+-.0.8)R.sub.2 O.aM.sub.2 O.sub.3.bM'O.cAl.sub.2 O.sub.3 !.ySiO.sub.2 in which R is at least one of alkali metal ions and hydrogen ion, M is at least one elementary ion selected from the group consisting of Group VIII elements of Periodic Table, rare earth elements, titanium, vanadium, chromium, niobium, antimony and gallium, M' is an alkaline earth metal ion selected from magnesium, calcium, strontium and barium ions, a>0, 20>b.gtoreq.0, a+c=1 and 3000>y>11, on which (I) at least one member selected from platinum group metals and (II) at least one metal selected from platinum group metals and at least one metal selected from the group consisting of rare earth elements are suppo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.