The Nobel Prize in Chemistry 1994 was awarded to George A. Olah "for his contribution to carbocation chemistry".
 

George A. Olah developed superacids that are much stronger than ordinary acids, are non-nucleophilic, and are fluid at low temperatures. In such media carbocations are stable and their physical properties can be observed, thus allowing details of their structures to be determined. Besides trivalent ions Olah demonstrated the existence of higher coordinate carbocations. These species do not violate the octet rule, but involve 2-electron 3-center bonding. Olah thus devised a way to keep the transient carbocations around long enough to study their properties. What he found revolutionized the understanding of organic chemistry, leading to new discoveries and improvements in the production of gasoline, plastics and pharmaceuticals, to name a few.
 

Olah's discovery completely transformed the scientific study of the elusive carbocations. His work has resulted in new methods for the conversion of straight chain hydrocarbons (when used in combustion engines these have very low octane number and they are also difficult to degrade biologically) into branched hydrocarbons that have high octane numbers and are more easily biodegradable.