Ostwald nitric acid process

The Ostwald process—converting ammonia to nitric acid via platinum catalysis—existed as an unrealized possibility for six decades before becoming industrially inevitable. The gap between discovery and deployment reveals how inventions emerge from convergence rather than individual brilliance.

In 1838, French chemist Charles Frédéric Kuhlmann discovered that platinum could catalyze ammonia oxidation to nitric oxide. The observation sat in laboratory notebooks for sixty years. The bottleneck wasn't knowledge—it was ammonia itself. Natural sources supplied nitrogen compounds cheaply enough that synthetic routes offered no advantage.

By the 1890s, concerns about finite nitrate reserves created the adjacent possible. Wilhelm Ostwald, working between 1900-1901, revisited platinum catalysis with systematic rigor. His 1902 German patent detailed platinum gauzes at 900°C achieving selective oxidation. The process worked in three steps: catalytic oxidation to NO, non-catalytic oxidation to NO₂, absorption in water yielding nitric acid. Ostwald won the 1909 Nobel Prize for his broader catalysis work.

But the process remained economically dormant until 1913. The reason: it required continuous, abundant ammonia feedstock that didn't exist. The Haber-Bosch process, perfected between 1909-1913, finally cracked atmospheric nitrogen fixation. The two processes formed a symbiotic cascade: Haber-Bosch produced ammonia from air; Ostwald converted it to nitric acid.

WWI transformed this cascade from agricultural curiosity to strategic necessity. By August 1914, Germany faced Allied blockades cutting off Chilean nitrate imports. BASF's Oppau facility scaled directly from laboratory to production. Historians consider it virtually certain Germany would have been defeated by early 1915 without synthetic nitrogen. Today, the Ostwald process accounts for over 90% of global nitric acid production—60 million tonnes annually, 80% becoming ammonium nitrate fertilizer.