Getting the metal out

Most rubber used in North American products these days is made synthetically from petroleum. But how do manufacturers get the rubber to become a consistent, solid material that enables the tires of your car to run smoothly?

It happens with the addition of hydrogen to rubber through a process called hydrogenation. The process makes the rubber in tires stronger and helps them last longer.

Hydrogenation also gives food products such as peanut butter a longer shelf life and it is used in petroleum refining and production of electronic devices, pharmaceuticals, and fertilizer.

Adding hydrogen to these materials, however, needs a catalyst — a substance that will enable hydrogen;s beneficial properties to kick into action. This catalyst has always been a microscopic amount of a metal, usually nickel, iridium or platinum.

The problem — metals can be toxic to all forms of life if they work their way into the environment. “There are no immediate health dangers from using the metals, but after long exposure in the environment, they can endanger all forms of life,” says chemistry professor and Canada Research Chair in Inorganic Materials and Catalysis Douglas Stephan.

But Stephan has found a way to add hydrogen to materials without using a metal. Instead, he is using more environmentally friendly compounds such as nitrogen and boron.

“Our work is in its early days and we have a lot of catching up to do. After all, hydrogenation has been in use for over a century. But we believe we’re onto something. If we can get the metal out of the process, it will lessen the negative impact metals have on the environment and make production cheaper for manufacturers.” As an added bonus, Stephan believes that not using metals will result in hydrogenation eliminating the trans fats added to foods.

Stephan also feels it is incumbent on the science community to pursue more environmentally friendly possibilities — with a dose of reality.

“There are two ways to prevent harmful effects on the environment. One is abstinence and most people won’t practice that. People will still drive cars, for example. The other way is to produce the material goods we want, but to do that in a more environmentally responsible fashion. That’s the innovation challenge for scientists. Our new theme has to be developing methods of production that give society what it wants, but in a much cleaner fashion.”