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Title: Pre-converted nitric oxide gas in catalytic reduction system

Abstract

A two-stage catalyst comprises an oxidative first stage and a reductive second stage. The first stage is intended to convert NO to NO{sub 2} in the presence of O{sub 2}. The second stage serves to convert NO{sub 2} to environmentally benign gases that include N{sub 2}, CO{sub 2}, and H{sub 2}O. By preconverting NO to NO{sub 2} in the first stage, the efficiency of the second stage for NO{sub x} reduction is enhanced. For example, an internal combustion engine exhaust is connected by a pipe to a first chamber. An oxidizing first catalyst converts NO to NO{sub 2} in the presence of O{sub 2} and includes platinum/alumina, e.g., Pt/Al{sub 2}O{sub 3} catalyst. A flow of hydrocarbons (C{sub x}H{sub y}) is input from a pipe into a second chamber. For example, propene can be used as a source of hydrocarbons. The NO{sub 2} from the first catalyst mixes with the hydrocarbons in the second chamber. The mixture proceeds to a second reduction catalyst that converts NO{sub 2} to N{sub 2}, CO{sub 2}, and H{sub 2}O, and includes a {gamma}-Al{sub 2}O{sub 3}. The hydrocarbons and NO{sub x} are simultaneously reduced while passing through the second catalyst. 9 figs.

Inventors:
; ; ;
Issue Date:
Research Org.:
Univ. of California (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
335429
Patent Number(s):
5891409
Application Number:
PAN: 8-839,895
Assignee:
Univ. of California, Oakland, CA (United States)
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Resource Relation:
Other Information: PBD: 6 Apr 1999
Country of Publication:
United States
Language:
English
Subject:
33 ADVANCED PROPULSION SYSTEMS; 54 ENVIRONMENTAL SCIENCES; NITRIC OXIDE; SELECTIVE CATALYTIC REDUCTION; CATALYSTS; OXIDATION; NITROGEN DIOXIDE; EXHAUST GASES; AIR POLLUTION CONTROL; CATALYTIC CONVERTERS; HYDROCARBONS

Citation Formats

Hsiao, M C, Merritt, B T, Penetrante, B M, and Vogtlin, G E. Pre-converted nitric oxide gas in catalytic reduction system. United States: N. p., 1999. Web.
Hsiao, M C, Merritt, B T, Penetrante, B M, & Vogtlin, G E. Pre-converted nitric oxide gas in catalytic reduction system. United States.
Hsiao, M C, Merritt, B T, Penetrante, B M, and Vogtlin, G E. Tue . "Pre-converted nitric oxide gas in catalytic reduction system". United States.
@article{osti_335429,
title = {Pre-converted nitric oxide gas in catalytic reduction system},
author = {Hsiao, M C and Merritt, B T and Penetrante, B M and Vogtlin, G E},
abstractNote = {A two-stage catalyst comprises an oxidative first stage and a reductive second stage. The first stage is intended to convert NO to NO{sub 2} in the presence of O{sub 2}. The second stage serves to convert NO{sub 2} to environmentally benign gases that include N{sub 2}, CO{sub 2}, and H{sub 2}O. By preconverting NO to NO{sub 2} in the first stage, the efficiency of the second stage for NO{sub x} reduction is enhanced. For example, an internal combustion engine exhaust is connected by a pipe to a first chamber. An oxidizing first catalyst converts NO to NO{sub 2} in the presence of O{sub 2} and includes platinum/alumina, e.g., Pt/Al{sub 2}O{sub 3} catalyst. A flow of hydrocarbons (C{sub x}H{sub y}) is input from a pipe into a second chamber. For example, propene can be used as a source of hydrocarbons. The NO{sub 2} from the first catalyst mixes with the hydrocarbons in the second chamber. The mixture proceeds to a second reduction catalyst that converts NO{sub 2} to N{sub 2}, CO{sub 2}, and H{sub 2}O, and includes a {gamma}-Al{sub 2}O{sub 3}. The hydrocarbons and NO{sub x} are simultaneously reduced while passing through the second catalyst. 9 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1999},
month = {4}
}