Haber process

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The principal commercial method of producing ammonia, by direct combination of nitrogen and hydrogen under high pressure in the presence of a catalyst, often iron.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun inorganic chemistry The nitrogen-fixation reaction of nitrogen gas and hydrogen gas, over an enriched iron or ruthenium catalyst, used industrially to produce ammonia.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun an industrial process for producing ammonia from nitrogen and hydrogen by combining them under high pressure in the presence of an iron catalyst