Selective Catalytic Hydrogenation of Fatty Acids with Cobalt–Halloysite Nanocomposites for Waste Valorization

Environmentally friendly catalytic composites based on cobalt and a natural clay as catalytically active phase and support, respectively, are herein reported for the valorization of fatty acids and esters, in particular for wastes coming from agri-food industry, by selective hydrogenation processes. The as-prepared innovative materials are constituted of zero-valent cobalt nanoparticles immobilized on both pristine halloysite and an ammonium-functionalized clay, with the former support exhibiting better particle distribution on the support as only Co agglomerates could be obtained for ammonium-functionalized halloysite. Under optimized conditions (5 mol % Co, 120 °C, 40 bar), high conversions and remarkable chemoselectivity were observed, leading to the exclusive formation of saturated fatty acids or esters, as well as the formation of tristearin used as a food additive.