Highly Active Nickel (II) Oxide-Supported Cerium Oxide Catalysts for Valorization of Glycerol into Oxygenated Fuel Additives.

Acetylation of glycerol to yield monoacetin (MAT), diacetin (DAT), and triacetin (TAT) over NiO-supported CeO ₂ ( x NiO/CeO ₂ ) catalysts is reported. The catalysts were synthesized utilizing a sol-gel technique, whereby different quantities of NiO ( x = 9, 27, and 45 wt%) were supported onto the CeO ₂ substrate, and hexadecyltrimethylammonium bromide (CTABr) served as a porogen. The utilization of EDX elemental mapping analysis confirmed the existence of evenly distributed Ni ²⁺ ion and octahedral NiO nanoparticles on the CeO ₂ surface through the DRS UV-Vis spectroscopy. The most active catalyst is 27NiO/CeO ₂ based on TAT selectivity in the glycerol acetylation with ethanoic acid, attaining 97.6% glycerol conversion with 70.5% selectivity to TAT at 170 °C with a 1:10 glycerol/ethanoic acid molar ratio for 30 min using a non-microwave instant heating reactor. The 27NiO/CeO ₂ is reusable without significant decline in catalytic performance after ten consecutive reaction cycles, indicating high structure stability with accessible active acidity.