Science News wrote an interesting article this spring that predicted a change to how catalytic converters are constructed that could result in decreased vehicle costs.
First, on March 26, engineers and researches at GM reported that the material perovskite, a calcium titanium oxide mineral found in the Ural Mountains of Russia, may do a more effective job of cleaning exhaust and removing nitrogen oxides from vehicles than traditional catalytic converters constructed out of costly platinum, which was recently traded for as much as $1,700 an ounce. A few years ago, this industry attuned to state and federal investigations surrounding a rash of stolen catalytic converters, some on school buses. Platinum is at a premium, and the black market is paying top dollar.
The existence of platinum and other valuable minerals in vehicle construction and engine emissions controls also affects purchase price, part of the reason why later-model school buses compliant with stricter EPA clean air regulations cost so much. Indeed, an April 24 Science News article stated that diesel cars can cost $1,000 to $5,000 more than comparable gasoline models because the engine must be modified and these expensive catalytic converters must be added to meet emissions standards.
“The problem is that diesel engines need to burn ‘lean,’ or in the presence of extra air, compared with regular gasoline engines. The extra oxygen makes it harder to remove nitrogen oxides,” wrote Alexandra Witze in the Science News article.
There have been rumblings in the industry that, with high diesel prices mixing with ever-increasing costs of diesel school buses, interest is growing in turning to gasoline options for school buses. But, as GM researchers have found, perovskite-based catalytic converters could provide another solution. When used in lieu of platinum-based catalytic converters, the perovskite product converted nitrogen oxides to nitrogen dioxide about as well the platinum products.
“We were looking for a good catalyst, but we were not expecting it to be that good,” commented Wei Lei, the leader of GM’s Global Research and Development branch in Warren, Mich.
