Metal–Organic Frameworks-Derived Cobalt Catalyst Supported on Biochar for Efficient Deoxygenation of Stearic Acid

Abstract

The conversion of stearic acid into linear hydrocarbons is a crucial step in advancing sustainable biofuels and biochemicals. Herein, we developed a series of cobalt-based catalysts (referred to as Co/C@TSC) using metal–organic frameworks (MOFs) as precursors and supporting them on biochar derived from natural tung shells (TSC). Tung shells, a byproduct of the tung oil extraction process, are widely available. The as-designed Co/C@TSC catalyst effectively deoxygenated stearic acid via decarbonylation/decarboxylation (DCO_x) processes, achieving a conversion of 78.5% and hydrocarbon product selectivity of 90%, specifically heptadecane and heptadecene. Our detailed analysis showed that the addition of biochar support improved the spatial distribution of cobalt species (with a high surface concentration of Co⁰) and enhanced the adsorption of reactants, thus boosting catalytic activity. Additionally, in situ DRIFTS analysis confirmed that the stearic acid deoxygenation process involved the intermolecular dehydration of stearic acid molecules. Experiments with different reaction substrates revealed that the stearic anhydride was a key reaction intermediate during the deoxygenation process. This study introduces a novel catalyst made from dual carbon-supported nonprecious metals, presenting a promising method for transforming stearic acid into valuable hydrocarbon products.