An Italian chemical engineer noted for his work on polymerization and the development of commercially important polymerization processes. After graduating from the Polytechnic of Milan, he began his career with the study of solids using X-rays and electron diffraction, which he extended to catalysts using the same methods. He was awarded the Nobel Prize in Chemistry in 1963, together with the German chemist Karl Waldemar Ziegler (1898–1973).