Sustainable Esterification of Fatty Acids Using Silica‐metal Bond Derived From Waste Copper Slag and Vanadium

ABSTRACT Esterification reactions are essential for producing many commercially valuable chemicals. Although waste copper slag poses a growing environmental concern, its high content of metal oxides (FeO, SiO 2 , Al 2 O 3 , CaO, and residual Cu) remains underutilized as a catalytic resource. The study addresses research gap by exploring copper slag as a sustainable catalyst for esterification, aiming to enhance catalytic efficiency while promoting waste valorization. Vanadium pentoxide (V 2 O 5 ) supported on wet copper slag (V 2 O 5 /Wet Cp‐Sl) was synthesized using the impregnation method and employed as a heterogeneous catalyst for esterification reactions aimed at producing biofuels, flavors, fragrances, surfactants, and biopolymers. The catalysts were thoroughly characterized using HR‐TEM, XRD, XPS, ATR‐FTIR, BET, EDX‐mapping, TGA, and ICP‐AES techniques. Esterification of oleic acid with methanol exhibited optimal catalytic performance at a 10 wt% V 2 O 5 loading on Wet copper slag, which showed 92.4% yield. The activation energy was calculated to be 13.4 kJ/mol, suggesting enhanced catalytic efficiency. The incorporation of V 2 O 5 led to the formation of Fe 3 + , Al 3 + , and Si–O–M species, strengthening metal–support interactions. The presence of redox‐active species such as V 4 + and Fe 2 + further contributed to improved catalytic activity. ATR‐FTIR studies identified the nature of active sites, while kinetic analysis evaluations confirmed a reduction in activation energy.