Science Buddies: "Ask an Expert"

Hello,

For my project, I tested different types of catalysts (platinum, copper, nickel, molybdenum) to determine which are the most (and least) efficient fuel cell catalysts, so I could then research the properties of an effective fuel cell catalyst.

I used the procedure at this link: http://sci-toys.com/scitoys/scitoys/ech ... _cell.html

According to my results, nickel is the best catalyst, and molybdenum is second-best. For copper and platinum, I got no results (the multimeter just showed zero). I know this shouldn't be right… platinum should be the most effective! I did exactly the same test with copper and platinum as I did with nickel and molybdenum, and I can't think of where something might have gone wrong. I'm not sure how to explain this in my paper. Please help!

Hi candy4me,

Fuel cells aren't my particular expertise; however, I can give some general pointers about how to deal with unexpected data.

First, getting data that doesn't support your hypothesis or match predictions from theory doesn't mean your science project is a failure. So, you don't need to worry about that.

Whenever we get data that don't make sense, it means something was going on in the experiment that we don’t understand. For example, sometimes unexpected data means there is a scientific principle at work that we didn't think about or didn't know about. At other times unexpected data tells us that we had a problem with our experimental design, so that we didn't measure what we thought we were measuring. Or, sometimes it's something as simple as a reversed connection on an instrument. But, the data are what they are. If they are unexpected, then the data themselves are clues to why we got unexpected results.

In your case, I would present the conclusions you can draw from your data. Remember that the data you collect dictate the conclusions you draw. Then, I would point out that your data don't match what you think should be the best catalyst. Pointing out the disagreement between your results and the platinum catalyst shows the people reading your report (teachers, judges, etc.) that you have thought carefully about your data. Finally, I would discuss various factors that might have led to the unexpected result. I'm afraid that I'm not much help with the specifics of what might have gone wrong in your particular experiment. But, the fact that the multimeter didn't give a reading for copper and platinum suggests that there may have been a problem with the multimeter's settings or the way it was connected to the fuel cell. Hopefully someone with more fuel cell expertise will chime in with additional details.

Thank you, this is very useful information. I will try to do some more research today to see if I can figure out what happened.