New York City ? A German scientist received a startling present Wednesday on his 71st birthday: a $1.5 million Nobel Prize to honor his groundbreaking studies of how chemical reactions take place on surfaces.

Gerhard Ertl laid the foundation for studies of modern surface chemistry, a field that will help scientists produce renewable energy more efficiently and create new materials for electronic devices, the Nobel committee said.

Surface chemistry is also important for many industrial processes, and key to understanding such diverse things as how pollution eats away at the ozone layer, fuel cells produce energy without pollution and catalytic converters clean up automobile exhaust.

Ertl showed how to get reliable results from technically demanding experiments and provided detailed descriptions of key chemical reactions, the Nobel committee said Wednesday.