Fabrication of NiZn bimetallic oxides catalysts supported on carbon black waste for catalytic pyrolysis of fatty acid

Herein, NiZn bimetallic oxides derived from calcination treatment of metal-organic frameworks (MOFs) were successfully loaded onto the carbon black waste as support obtained from the oil refinery. The resulting hybrids could serve as environmentally friendly and cost-effective catalysts for the deoxygenation of biomass-derived fatty acids under an inert atmosphere. An online pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) system was employed to evaluate their deoxygenation performance. The optimized catalysts demonstrated remarkably high stearic acid conversion of 99.6% and selectivity towards C8-C17 olefins of 57.2%. Furthermore, these catalysts with varying metal loadings also exhibited excellent efficiency in deoxygenation reactions of other types of fatty acids, such as myristic acid and palmitic acid, achieving conversion exceeding 85% and selectivities towards olefins of ca. 50%. When converting coconut oil, the supported NiZn bimetallic oxides showed excellent selectivity towards olefins (>60%). Furthermore, in-situ DRIFTS results suggest that fatty alcohols might be the key intermediates in the deoxidation reactions of fatty acid. This study not only demonstrates the great potential for obtaining valuable chemicals from biomass but also provides some insights into the fabrication of catalyst materials by using industrial solid waste.