Gabor A. Somorjai is a professor of chemistry at the University of California, Berkeley, and is a leading researcher in the field of surface chemistry and catalysis, especially the catalytic effects of metal surfaces on gas-phase reactions. For his contributions to the field, Somorjai won the Wolf Prize in Chemistry in 1998, the Linus Pauling Award in 2000, the National Medal of Science in 2002, the Priestley Medal in 2008, the 2010 BBVA Foundation Frontiers of Knowledge Award in Basic Science and the NAS Award in Chemical Sciences in 2013. In April 2015, Somorjai was awarded the American Chemical Society's William H. Nichols Medal.

The Priestley Medal is the highest honor conferred by the American Chemical Society (ACS) and is awarded for distinguished service in the field of chemistry. Established in 1922, the award is named after Joseph Priestley, one of the discoverers of oxygen, who immigrated to the United States of America in 1794. The ACS formed in 1876, spearheaded by a group of chemists who had met two years previously in Priestley's home.