Single‐step conversion of levulinic acid to valeric acid over bimetallic Ni‐Co/H‐ZSM‐5 catalysts

Abstract

AbstractSingle‐step conversion of levulinic acid (LA) to valeric biofuel is extremely promising for the development of bio‐refineries. Direct conversion of LA to valeric acid (VA) was investigated over H‐ZSM‐5 supported Ni, Co, and Ni−Co (different Ni/Co wt. % ratios) catalysts under ambient reaction conditions (543 K and atmospheric pressure) in the gas phase. Compared with supported monometallic catalysts, bimetallic Ni−Co catalysts exhibited more activity and selectivity toward VA production. Among Ni−Co/H‐ZSM‐5 catalysts, 15Ni‐5Co/H‐ZSM‐5 catalyst is optimum with 97.5 % conversion of LA and 63 % selectivity to valeric acid even after 6 h time‐on‐stream (TOS). The active metallic sites are responsible for the hydrogenation of LA to γ‐valerolactone (GVL), and acidic sites catalyze the conversion of GVL to VA. All the catalysts were characterized using the XRD, H2‐TPR, N2‐adsorption‐desorption isotherms, NH3‐TPD, Py‐IR, SEM, HR‐TEM and XPS techniques.