Patent · US Expired

Catalyst for purifying exhaust gas

US6066587A · kind A · utility

83Cited by
23References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 25, 1997
Grant dateMay 23, 2000
Priority date
Expiry dateSep 25, 2017

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02T10/12
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

A catalyst has a base catalyst layer containing platinum and barium as precious metal supported by alumina and an over catalyst layer containing platinum and rhodium as precious metal supported by zeolitr. The platinum and rhodium in the over catalyst layer activate NOx and HC so as to make them more reactive in terms of energy, and the barium in the base catalyst layer makes the platinum be more dispersive in the base catalyst layer. Under the existence of dispersive platinum, NOx in exhaust gas is decomposed and purified by reaction with reactive NO.sub.2 and partially oxidized HC generated in the over catalyst layer.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.