Adding Value to Waste Minerals in a Circular Economy Framework: Ochre-Derived Layered Double Hydroxide Catalysts in Fatty Acid Ketonisation

Transforming waste materials into added-value products is critical for a sustainable and circular economy. Here, Mg/Fe layered double hydroxide (LDH) materials, with a Mg2+:Fe3+ ratio of 2, were successfully synthesized via the co-precipitation method from a dissolved acid mine drainage precipitate waste “ochre”, which is normally put to landfill. The prepared LDH materials were tested as a heterogeneous base catalyst to promote the production of the ketone, 12-tricosanone, from lauric acid, a component of plant oils, through a ketonic decarboxylation reaction, giving a circular economy route to catalysts for sustainable ketone production. The highest yield of the ketone observed was 80%.