Talk:Catalytic converter

Bead-type converters
This article presently lacks any discussion or image of the bead (or pellet) catalytic converter configuration as used on GM (and possibly AMC) vehicles from 1975 through much later than one would think. This is a fairly serious omission; let's have some omission control. —Scheinwerfermann T·C 03:11, 11 February 2012 (UTC)
 * I might be able to dig up some free images, I know some people who may be willing to make a donation :) But it may take a while, I'm in the middle of moving. UrbanTerrorist (talk) 04:33, 14 June 2012 (UTC)

add diagram
Please add a diagram (or make one) of the internal structure of a typical catalytic converter.--Gauravjuvekar (talk) 14:00, 13 February 2012 (UTC)
 * Are you going to pay for me to do a CAD drawing? If you are, I'll happily do one. If you just want to look, you can see a basic drawing | here. UrbanTerrorist (talk) 04:48, 14 June 2012 (UTC)

1960s nickel platinum catalytics?
I am aware of some important work done in the 1960 s which made the first automotive catalytic converters cost feasible by the use of a nickel platinum alloy which cut the cost from around $2000 to around $500 per unit. I understand that this alloy was patented at Gulf Research and Development(now part of Chevron). Does anyone have any additional information about this?Billinbizz (talk) 19:09, 6 July 2013 (gjgh_)

First Standard Fit of Catalytic Converters to Production Automobiles
Further digging turned up the book "A Standard Catalog of Chevrolet, 1912-2003: 90 Years of History, Photos, Technical Data and Pricing" written by John Gunnell. It documents the fitting of converters to the 1974 Chevrolet Camaro, but does not give any reason for why the converters were fitted on year before the regulations would have required them. This book was published in November 2011, after our original discussion, and indicates that the converter was fitted to all Camaro models, with all engines. The book is available on | Google Books. An earlier book by the same writer, the 2004 Camaro White Book states that the | catalytic converters where first fitted to the 1975 model year. It appears that the writer has been doing more research. It's hard to be certain, but it looks like the "90 Years of History" book may have been done with General Motors assistance. UrbanTerrorist (talk) 04:45, 14 June 2012 (UTC)


 * Wow, lookit there, you're still bound and determined to find a way to believe in those imaginary 1974 Camaro catalytic converters! Well, good for you; I admire your persistence even in the face of silence from the community. The simplest and most likely explanation for what you think you've found is sloppy fact-checking and editing of the "Standard Catalog"; it's unfortunately endemic to that series of books. Don't despair, though; you can still prove you're right and the existing mountain of reliable sources is wrong with the direct-from-GM info your super-secret inside man at GM was going to send you. That was in December of 2011; he's probably off the phone by now and ready and willing to help you out. (And BTW, HEI arrived in '75, not '74. Just like Catalytic converters. Another "Standard Catalog" fact-fail.) As for "General Motors assistance" in writing the book you found: I see no such evidence, and I think you'll have a hard time supporting your guess (wish?) on that point. —Scheinwerfermann T&middot;C 00:30, 15 September 2012 (UTC)


 * So you would rather believe a newspaper than a book put together with General Motor's assistance? FYI, my buddy says he wasn't involved with the Camaro. UrbanTerrorist (talk) 01:21, 3 November 2012 (UTC)
 * So you're going to try to parlay your baseless guess/fabrication-outta-thin-air that the book you found was written "with General Motors assistance" into received wisdom by repeating it, eh? Pfft. No sale. And go get your vision checked; the collossal mountain of reliable source for the 1975 assertion cannot be described as "a newspaper".


 * As for your secret buddy at GM: So! He didn't actually work on the Camaro as you were sure you remembered, eh? Gosh...that's almost enough to make one question what else one might not be remembering quite so correctly as one thought one was! There comes a time, UrbanTerrorist, when the grownup thing is to say "I guess I could've been mistaken", let it drop, and move on. That time passed on this issue awhile ago. Can we expect you to catch on and behave like a grownup? —Scheinwerfermann T&middot;C 01:53, 3 November 2012 (UTC)


 * There's no doubt that the newspapers reported what they knew. They just didn't know everything, and you wouldn't expect them too. As to being "mistaken" as you put it, since I know I'm not, I'm going to keep digging up more bits. So far I've given you a parts manual page for a 1974 car with a catalytic converter, and a book written with GM assistance. How much do you require? UrbanTerrorist (talk) 04:32, 14 November 2012 (UTC)

Platinum in car batteries?
I recall reading somewhere that some of the modern sealed automotive batteries contain a platinum coated wire that converts H2 and O2 gases (a result of overcharging a lead-acid battery) back to water vapor. Is this true? This suggests another catalytic reaction that is not indicated in the article. Someone with expertise - please verify and update article accordingly. --96.244.244.244 (talk) 01:53, 9 August 2012 (UTC)


 * Perhaps it's true—I've never heard of such a thing, but I'm not a car battery expert. If a reliable source can be found to support the assertion, that information would belong not in this article but in automotive battery and/or Lead-acid battery. —Scheinwerfermann T&middot;C 01:29, 15 September 2012 (UTC)

Environmental impact
reference 27 is a New York Times article and not a serious reference; the section gives a negative impression - it should be made clear that there was a huge improvement in air quality since the introduction of catalytic converters; catalytic converters have essentially no influence on CO2 emissions thus the first two phrases on CO2 and global warming have no point here. 131.211.44.165 (talk) 17:36, 4 October 2012 (UTC)epo — Preceding unsigned comment added by 131.211.44.165 (talk)


 * Er…sorry, anonymous editor, but the New York Times is an unassailably reliable source. —Scheinwerfermann T&middot;C 00:17, 5 October 2012 (UTC)


 * Source is good, NYT is more accurate them most, but the article is obsolete, from May 29, 1998. It was correct when written, but things have changed since then. I'll update the section, and cite the data on the Environmental Protection Agency website. UrbanTerrorist (talk) 04:43, 14 November 2012 (UTC)

CITE Request on Diesel Engines not using 3-Way converters
Removed - explanation is in the main body of the article. UrbanTerrorist (talk) 04:44, 14 November 2012 (UTC)

Missing citation
I'm not really sure how to add a missing citation to the wiki, but #26, http://www.bnl.gov/ps/about/everyday/catalytic.asp leads to a 404. moeburn (talk) 13:50, 24 December 2013 (UTC)

Suicides/Accidental Deaths Reduced
It might be worth mentioning that by removing CO from the exhaust gases these converters have made it very difficult to commit suicide by the 'traditional' way of simply driving into ones garage and closing the garage door. Cassandra — Preceding unsigned comment added by 92.12.110.237 (talk) 15:56, 5 June 2014 (UTC)
 * The usual accidental CO poisoning comes from power generators, which burn less cleanly, in addition to no catalytic converter. If you run the car long enough in a closed garage, it will reduce oxygen, and so increase CO (relative to CO2) production. But it won't be fast. Gah4 (talk) 22:28, 13 March 2022 (UTC)
 * The usual accidental CO poisoning comes from power generators, which burn less cleanly, in addition to no catalytic converter. If you run the car long enough in a closed garage, it will reduce oxygen, and so increase CO (relative to CO2) production. But it won't be fast. Gah4 (talk) 22:28, 13 March 2022 (UTC)

Not just for vehicles
The first sentence in this article claims CCs are for vehicles, but they're also used on kerosene stoves and heaters. This articles makes absolutely no mention of these applications whatsoever. 24.51.217.118 (talk) 09:59, 3 October 2015 (UTC)
 * As far as I know for heaters, they are part of the heater itself. That is, not for emission reduction as for cars. For a radiant heater, some metal (usually) gets red hot. The usual way to do that, is to have the fuel and oxygen react on the metal surface, catalytically. I suspect that means that they should have their own article. Gah4 (talk) 01:55, 5 January 2022 (UTC)
 * As far as I know for heaters, they are part of the heater itself. That is, not for emission reduction as for cars. For a radiant heater, some metal (usually) gets red hot. The usual way to do that, is to have the fuel and oxygen react on the metal surface, catalytically. I suspect that means that they should have their own article. Gah4 (talk) 01:55, 5 January 2022 (UTC)

Carbon nanotube production
A new paper has identified automotive catalytic converters as a source of carbon nanotube pollution, found in the upper airways of asthmatic Parisians. It seems the converters are very similar to a well-known CNT production technique using high-pressure carbon monoxide. LeadSongDog come howl!  15:46, 30 October 2015 (UTC)

These three reactions occur most efficiently when the catalytic converter receives exhaust from an engine running slightly above the stoichiometric point
The above sentence is in the original Wiki page. It should be explained further with proof.2607:FEA8:C31F:FDDB:910B:4067:52B9:1BEC (talk) 17:43, 14 April 2017 (UTC)
 * It wasn't obvious to me whether above means more or less oxygen. Should it explain that? Gah4 (talk) 02:01, 5 January 2022 (UTC)
 * It wasn't obvious to me whether above means more or less oxygen. Should it explain that? Gah4 (talk) 02:01, 5 January 2022 (UTC)

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"Efficiency" and "above the stoichiometric point"
The sentence ---> "These three reactions occur most efficiently when the catalytic converter receives exhaust from an engine running slightly above the stoichiometric point. For gasoline combustion, this ratio is between 14.6 and 14.8 parts air to one part fuel, by weight." <--- is rather poor / confusing. Cat's chemical reactions work best when cycled slightly rich and lean (above and below 14.7). Can someone tidy up this and make it clearer. I hope I'm not thick, I understand the principals not really the chemistry (that bit can come later by clever people) - thanks. — Preceding unsigned comment added by 109.145.20.92 (talk) 10:21, 27 August 2017 (UTC)

Edit for "Negative aspects"
The sentence "In addition, the transformation of nitrous oxides in to CO2 and water will cause..." is of course impossible. Maybe this refers to nitric acid production? This deserves a little further explanation. 'in to" should be replaced with "into" 139.80.19.241 (talk) 01:33, 19 July 2019 (UTC)
 * In the discussion of three-way catalytic converters, it is hard to understand what are the three reactions under consideration. It looks as if there are seven of them, split into two groups. — Preceding unsigned comment added by 66.41.200.182 (talk) 13:09, 1 March 2021 (UTC)
 * Well for one, that should be nitrogen oxides, to include all of them. They go to nitrogen gas, along with water and/or CO2, depending on what else there is. Conversion of HC and CO is done in oxidizing conditions, and of NOx in reducing conditions. That is the complication of three-way, and why they took longer to appear. Gah4 (talk) 17:10, 16 January 2022 (UTC)
 * Well for one, that should be nitrogen oxides, to include all of them. They go to nitrogen gas, along with water and/or CO2, depending on what else there is. Conversion of HC and CO is done in oxidizing conditions, and of NOx in reducing conditions. That is the complication of three-way, and why they took longer to appear. Gah4 (talk) 17:10, 16 January 2022 (UTC)
 * Well for one, that should be nitrogen oxides, to include all of them. They go to nitrogen gas, along with water and/or CO2, depending on what else there is. Conversion of HC and CO is done in oxidizing conditions, and of NOx in reducing conditions. That is the complication of three-way, and why they took longer to appear. Gah4 (talk) 17:10, 16 January 2022 (UTC)

value
It would be nice to know the (approximate) value of the precious metals. As well as I know, they are in very thin layers on beads, or some other high surface area material. That the amount in any one converter is pretty small. Presumably worth recycling, but is it really valuable enough for so many CC thieves? Gah4 (talk) 02:03, 5 January 2022 (UTC)

Catalytic converter BMW Z4 2005
Catalytic converter required for above car 82.36.82.98 (talk) 10:03, 15 February 2022 (UTC)


 * This is Wikipedia, not autozone. Go look up your car parts on their site. 2601:410:8002:1AE0:CD45:7679:49C5:19B1 (talk) 01:02, 10 September 2023 (UTC)

history
Passenger cars got cats in model year 1975, when did light trucks start? How about heavy duty trucks? Anyone able to fill in a little more history here?

Thank You 24.102.129.229 (talk) 14:55, 17 February 2022 (UTC)Randy

Questions not answered in the article
In Europe, they had G-Kat and U-Kat for a while - both are three-way catalytic converters, but the U is "unregulated." It does not have a lambda sond, but just sends the exhaust through the catalyst. This article, however, does not mention these and also does not contain the word "lambda", which seems like an oversight. Beyond my technical expertise to write about; someone please help!  Mr.choppers &#124;  ✎  03:54, 17 January 2024 (UTC)

EGR
For 2-way converters that don't reduce nitrogen oxides, as well as I know it, EGR was used, which reduces combustion temperature and so nitrogen oxide production. Gah4 (talk) 21:33, 17 February 2024 (UTC)