With all of the technological advances lately, couldn’t a catalytic converter be designed with cheaper materials that aren’t worth stealing?
In: 2057
It’s a problem that, at this point, would be pointless to solve. The age of the internal combustion engine is coming to a swift end, and the only ICE cars on the road in the decade will be used cars. Those will slowly dwindle, and catalytic converters will go the way of the dodo.
I think with the shift towards electric cars, why would they reinvent the catalytic converter which isn’t required with an electric car
I work closely in this area, so I’ll be able to explain this to different complexity extents.
The answer is YES, but there are some caveats.
First of all, we need to understand **why we need a catalytic converter.** When internal combustion engines burn fuel there are harmful and undesired gases that are produced and that we don’t want to emit. The most important ones are *nitrogen oxides*, *carbon monoxide* (not to confuse with carbon dioxide or CO2) and *unburned fuel.* **Therefore, the catalytic converter was designed with the objective of reducing the emission of these gases.**
Second of all, we need to understand **how a catalytic converter works.** When gases come out of the engine and start passing through the catalytic converter, each of the harmful gases mentioned above will be converted into harmless gases with the help of specific metals. Here it is important to clarify something. This might be out of ELI5, but it is still very important to mention it. Which metal helps convert which gas depends on the nature of the reaction. For example, carbon monoxide and unburned fuel will need to be oxidized and nitrogen oxides will need to be reduced. When oxidation occurs, the harmless gases coming out are carbon dioxide and water and when reduction occurs, the harmless gas will be nitrogen and water. **In summary, specific metals in the catalytic converter help convert the harmful gases into harmless ones.**
Now, if we limit this discussion to engines using gasoline and Diesel, the metals used in catalytic converters in gasoline cars use Rhodium and Palladium to help reduce nitrogen oxides and Platinum to help oxidize the carbon monoxide and unburned fuel (Palladium can also contribute). Similarly, in Diesel engines, Platinum and Palladium help oxidize carbon monoxide and unburned fuel but in the case of reducing nitrogen oxides we use Copper, which is very cheap!
Rhodium is currently the most expensive metal of the three, followed by Palladium and Platinum. If you wanted to replace those metals, you would need to find other cheaper metals that can interact similarly. These metals actually exist but there are more variables that prevent them from becoming a final product. A second clarification, these compounds that are used to help convert the harmful gases are called *Catalysts*.
To give you an example, currently there are catalysts that are based on Copper and Cerium Oxide which are excellent for oxidation reactions and which can actually be more efficient than Palladium and Platinum ones. These catalysts are first tested at laboratory scale under simpler conditions and if they show promising performance, then, they are tested under more realistic conditions. You might ask yourself, why don’t we use this catalyst in industry? As it turns out, there are other important aspects to take into account to commercialize them. One of them is resistance to poisoning from sulfur which is present in fuels and unfortunately reduces the performance of the catalyst over time.
So, to summarize, yes, currently there are replacements with cheaper metals which work very well under somewhat ideal conditions and current research work involves improving other aspects that hinder the commercialization of the catalysts.
If people want me to explain more aspects in more detail, I would be more than happy to do it 🙂
Source: I’m a PhD in Chemical Engineering focused in the area of catalysis with emphasis in vehicle emission control.
VW makes something like 10 million cars a year. Some of those cars have 2 cats, some 1, and some probably none. Call it an average of 1 cat per car at about $200 a piece for cost.
Rest assured if there was a way to do it VW would gladly do it as it would cut 2 billion off of their expenses every year.
I don’t have an answer, but rather a couple of questions.
How much are thieves actually getting, approximately, for a stolen catalytic converter?
You can get a universal catalytic converter for less than $50. Many years ago, I had a 91 Honda Civic that failed smog test. I had my mechanic replace it, he used a generic one. FYI, I never instructed him to half ass or cheat. The guy ran a legitimate business, was licensed and insured, everything was officially invoiced, and accepted pretty much all forms of payment, etc. I don’t remember the total cost of the job, however I do remember being surprised that his (marked up) price on the converter itself was only a small portion of the bill, under $100, I think, though I wouldn’t swear to it. The car then passed the smog test with flying colors, and continued to do so for another few years till I got rid of the car.
What is it about these “universal” catalytic converters that allows them to be so cheap? I’d think that of they didn’t actually do what they’re supposed to, or wear out quickly or what not, the EPA would be all over it. So, what gives?
The chemistry isn’t there.
The reaction must take exhaust gasses, and output and convert a certain percentage of it into something eco friendly and non-harmful.
Hard to say what chemicals fit that bill…
But it’s REALLY hard to argue convincingly that water isn’t “eco friendly and non-harmful”.
So, you know the reactant, and you know the resultant.
You just need to find the most cost effective catalyst to do it.
And that catalyst itself has to be eco friendly and non harmful. They have to be pretty durable, and also withstand VERY high exhaust temperatures. 1300 degf for a new toyota corolla. Hot enough to make mild steel glow dull red.
And it needs to not oxidize a whole lot when it gets that hot… most metals do.
So it has to be HIGHLY inert even at high temperatures. But reactive in just the right way to output water.
High temp oxidization resistance… (platinum group metals).) relatively durable mechanical properties (platinum group metals)… highly inert (platinum group metals)… largely non toxic by itself (platinum group metals)…
Surprise of all surprises… the stars align on only a few chemicals… solid at those temps, oxidization resistant, reasonably strong, highly inert, and output what we want.
Properties of materials are guessable to some extent.
Nothing presently (save possible exotic materials) has any chance of being useful for that application.
So, the cheapest materials for the cause, wind up being… the ONLY materials for the cause. Because all of those attributes are rare, and incredibly rare together, naturally the price of that material is high.
Chemist here: there is vast research being done on non-precious metal catalysis. Not only for catalytic converters but im sure its being done as well. Its just the platinum metals have the correct properties. There is bunch of stuff you can do with nickel ir copper but (in organic chemistry for making new compounds) palladium is by far the most versatile and most used.
The Pd stuff is like 20-30 yrs old, nobel prize worthy but the nonprecious metals in catalysis are not as developed so we can hope
Even if there is, car manufacturers probably aren’t putting a lot of money into R&D there.
The car market is going electric, which will reduce demand on catalytic converter materials. Reduced demand will reduce price, and reduce theft.
In engineering there is a saying: “*you can’t cheat physics or chemistry*”. What makes the catalytic converter is the precious rare metals of Palladium and Rhodium. Yes you could use cerium, iron, manganese, nickel and copper however these have all downsides or make other dangereous compounds.
You can’t cheat chemistry or physics.
Probably not.
The cheapest catalysts we have now are platinum, rhodium, and palladium, and none of them are cheap. So suppose Elon Musk invests a billion or two dollars into developing a material that replaces all three. Great job, Elon! Oh — and here are your royalties, because obviously after putting billions of dollars into developing Muskium you’re not giving it away for nothing. So great, there are no precious metals in the catalytic converters anymore; oh darn, people are stealing them because they’re full of Muskium. Tl;dr: the chemistry’s tough, but the economics are absolutely brutal.
And when you look at the economics, it doesn’t make sense to put billions of dollars into something that cleans up dirty engines’ emissions when you could put that money into making clean engines — or into designing cities where you don’t need a car to survive. Or both.
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