(513j) Surfactant Assisted Self Assembly of Mesoporous NiO Catalysts for the Deoxygenation of Oleic Acid

With recent momentum towards the industrialization of renewable fuels in the energy sector, motivated largely by climate change and depleted fuel reservoirs, heterogeneous catalysts capable of removing oxygen from bio-resources are of mounting importance. Deoxygenation of fatty acids derived primarily from microalgae, animal fats, and used cooking oil offers great potential as a renewable fuel resource. Fatty acids of high abundance in these feedstocks include long chain saturated stearic acid and unsaturated oleic acid. Previously reported catalysts with high activity for the deoxygenation of fatty acids utilized rare earth metals including platinum and palladium. In recent years, nickel was reported to promote deoxygenation, providing an earth abundant and relatively inexpensive active phase.

Herein we report the surfactant assisted self-assembly of NiO catalysts. Structure directing agents CTAB and P123 were used to direct the formation of microspherical mesoporous NiO particles. The resultant catalysts were similar in chemical composition but differed in physical properties such as surface area, mesoporous ordering, and primary pore size. The mesoporous particles were used as catalysts in the deoxygenation of oleic acid. The catalysts derived from the P123 surfactant gave the highest yields to heptadecane (63%) tripling the performance of commercial NiO (19%). A phase change from NiO to Ni was observed during the deoxygenation reaction. This phase change was advantageous in the separation of the magnetic Ni particles from the reaction mixture, but also may have resulted in a weakened mesostructure during the reaction. The recyclability of the P123 derived catalyst was also evaluated.