Palladium is really neat stuff. It has an almost absurd affinity for hydrogen - it's one of a few metals we can use as something other than a salt or complex (i.e., just the metal). Pd on C is just carbon dust covered with 5 or 10% Pd metal (you can't see it - it's very expensive copier toner looking stuff).
Pd can transfer H2 to unsaturated functional groups. It can also break down molecules without actually "burning" them - your catalytic converter actually has a good deal of Pd in it. Ford lost a load of money some time back investing in Pd expecting to need to stock up (when cats were coming to be standard equipment in cars), but the price tanked.
Such a process is used to convert oils to anything from buttery stuff (margarine), to lardy stuff, to what's basically wax. "Partial" hydrogenation (Between oil and wax) can result in the much-maligned trans-fats.
Why worry about drawing software at all?
You can get lots of chemical structure images with palladium from PubChem. Click any one of the images and you'll get a pretty structure for posting.
I thought that catalytic converters had platinum as a catalyst?
It was also the metal of choice for making electrodes for cold fusion reactors, if you recall that amusing debacle. I know several people who bought up quantities of palladium as an investment, watched the price soar as the cold fusion story got hotter, and then saw it crash as the story died.