The paper discusses the CF-industries ammonia plant in Donaldsonville, Louisiana. The plant is framed as an exemplary site from which the Anthropocene can be observed and understood. In doing so, a proposal for a “chemical cultural theory” is set out, to allow us to understand such molecular planetary technologies and interpret their (geo)historical significance. As one of the largest fertilizer plants in the world in terms of its output, and one of the largest chemical plants along the “Petrochemical Corridor,” a cluster of chemical industries situated between Baton Rouge and New Orleans, Donaldsonville typifies the relations between the nitrogen and hydrocarbon industries. Catalysis is here used both as a chemical concept and as a metaphor central to the proposed chemical cultural theory. As key to the Haber-Bosch process and refinery technologies in general, investigating the role of catalysis allows us to connect the history of the Petrochemical Corridor to that of German industrialism. This relation reveals how, from the late 19th century through to the World Wars, an ambivalent industrial co-operation between the US and Germany not only transformed local and planetary environments, it also contributed to the Anthropocene condition.