The synergistic combination of solid catalysts and plasma for the synthesis of ammonia has recently attracted considerable scientific interest. Herein, we explore MgTiO₃, CaTiO₃, SrTiO₃, and BaTiO₃ perovskites as effective catalysts for the synthesis and decomposition of ammonia via cold plasma. MgTiO₃ perovskite, which contains the most electronegative alkaline metal of all the studied perovskites, resulted in the highest ammonia synthesis rate with a value of 12.16 μmol min⁻¹ m⁻², which is around 50 times the value of only plasma, 0.24 μmol min⁻¹. The high electronegativity of Mg can be assisting the dissociation of the triple nitrogen covalent bond. This intrinsic property of Mg perovskite added to the homogeneity of the plasma arising from the dielectric constant value of this perovskite might be synergistically responsible for the high ammonia synthesis rate observed. Interestingly, ammonia production over MgTiO₃ perovskite is almost double the performance of traditional oxides and some microporous crystals. We also explored the ammonia decomposition reaction due to the possibility of the importance of the reversible reaction owing to the electron collision with the ammonia molecules formed. Ammonia decomposition increased as plasma power increased. This points out the benefit of running at low plasma power and the need to design plasma reactors where the newly formed ammonia molecules can be removed from the reaction system to avoid further electron collision. The highest ammonia decomposition yield was 44.37% at 20 W corresponding to an energy yield of 5.06 g-NH₃ kW h⁻¹.

For the production of sustainable biofuels from lipid biomass it is essential to develop non-noble metal catalysts with high conversion and selectivity under inert gas atmospheres. Herein, we report a novel cobalt-based catalyst supported on zeolite NaX via ion-exchange synthesis. The resultant bifunctional cobalt-based NaX zeolite catalyst displayed high conversion of stearic acid to liquid fuels. In addition, the effect of reaction temperature and catalyst loading was studied to evaluate the order of reaction and activation energy. Decarboxylation and decarbonylation were the dominant deoxygenation pathways. Stearic acid was successfully deoxygenated in N₂ atmospheres using Co/NaX catalysts with a conversion as high as 83.7% and a yield to heptadecane up to ~28%. Furthermore, we demonstrate that higher reaction temperatures resulted in competing pathways of decarboxylation and decarbonylation. Finally, the fresh and recycled catalysts were characterized showing modest recyclability with a ~12.5% loss in catalytic activity.