What's this about platinum based catalytics?(Toyota rep is "not at liberty to talk"?)

He isn't saying that the existence of platinum based catalytics are hush-hush.

In fact, they are very common - it's the most common form of catalytic converter around !!

However, they have a bit of a problem that they tend to also make hydrogen sulfide as well as the intended gases.

That's because, being a catalyst, it encourages chemical reactions including getting any trace amounts of sulfur in the fuel to react with the hydrocarbons - making hydrogen sulfide.

That's why the traditional platinum based catalytic converters are being replaced with fancier ones - basically they add some coating and alloys (such as nickel) to try and discourage sulfate from reacting while encouraging the normal reactions.

It is quite a clever process - but it is in fact the OPPOSITE of the meaning you are getting.

Platinum based catalytics aren't new and being hushed up - they are old and the car reps aren't exactly go on record saying "Yes, we know our cars make poison !"

The levels are incredibly, incredibly low - and could be made lower by removing the sulfur from the fuel before use (which is very expensive).

However, with a LOT of cars, all those low emissions start adding up.

Mac

Mac H. said:

Platinum based catalytics aren't new and being hushed up - they are old and the car reps aren't exactly go on record saying "Yes, we know our cars make poison !"

Click to expand...

As I understand it, the major metal used in catalytic converters isn't platinum, but palladium. Palladium (now go check your periodic table, class) is the element directly above Platinum in the periodic table. It shares close chemical characteristics with platinum, but is lighter and costs about 1/4 as much. It is generally found and produced along with platinum. Palladium is traded on commodity exchanges as a precious metal, along with platinum, gold, silver and rhodium, and is used in making jewelry. It's hard, shiny and makes a good coating. It also has the capacity to absorb harmful exhaust gases, thereby the catalytic converter use.

caw

A bunch of transition metals have been experimented with to convert small-chain hydrocarbons (the sort easily produced from plants) into large-chain and aromatic hydrocarbons (the sort found in crude oil) since the 1980s (my wife did her research thesis on this very topic). This isn't so much because you need those suckers to drive cars (simple little molecules like ethanol burn just fine), but because you need them for lubricants and plastics, without which our industry grinds to a halt -- so if there's no oil with such stuff ready-made, you're forced to try and squeeze it from coal, or build it from alcohols and acids derived from starches and sugars -- or come up with something quite different.

The catalysts work, but that doesn't mean they work cheaply. Even with catalysts helping, you still need energy to do quickly what heat and pressure did over millennia -- join little hydrocarbons into bigger ones. And the energy needs to come from somewhere, of course.