Monday, March 19, 2012

Zirconium Rhymes With Titanium


Zirconium has a long, illustrious history in jewelery. The element's name derives from an ancient word for the gemstone, zircon.  The element is more commonly found in cubic zirconia, which--thanks to the Soviet method for making it using the so-called skull process--is cheap and plentiful.


Zirconium rhymes with titanium. Often, such transition-metal family members mimic each other. Zirconium, like titanium, is a valuable catalyst for making plastics. I know--yawn. But catalysis is an intellectually interesting aspect of chemistry--one which has "real-life" analogy--much like status quo and change.

Catalysts are classified as "heterogeneous" or "homogeneous" depending on whether they mix freely with hoi polloi substrates. "Heterogeneous" means that the catalyst stays in a different phase than whatever it's working on--e.g., a catalytic converter working on gas phase exhaust. Homogeneous catalysts swim in a liquid phase like everything else around it--in a single phase.

First generation Ziegler-Natta catalysts were heterogeneous. Catalysis happened at the edges or face of a chunk or pellet.  Obviously, a lot of unused catalyst lies buried inside- and is wasted. Homogeneous catalysts are known for their "atom efficiency"-- a concept that becomes more important for rarer platinum group metals.

2 comments:

  1. But, but, but what about hafnium!? How many "spotlight" articles have you done, focusing on the elements, without giving hafnium its fair due? Where's the justice? Where's the respect? I know it's an obscure one, with God knows how little use. But someday it will achieve prominence and fame... A use will be found that will blow the entire world away - to smithereens! I just feel it. Maybe it will be the first fuel for successfully carrying out cold fusion.

    Plus, it has a really cool name.

    Just you wait, other elements! Hafnium will have its say one day, and you'll all be jealous then! And sorry!

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  2. Dude, you have no clue what I intend to do with halfnium--all inspired by a comment you made here a few months ago.

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