Synthesis and use of a nano-crystalline zinc chromite catalyst, comprising nano-palladium

摘要

Several metal-supported catalyst compositions based on nano-crystalline zinc oxide were synthesized and characterized by X-ray powder diffraction (XRD), Carbon dioxide temperature programmed desorption (CO₂ TPD), and nitrogen adsorption at -196°C. The Pd-supported nano-ZnO mixed with different oxides such as Cr₂O₃, CrO₃, MgO, and γ-A1₂O₃ showed high catalytic activity in acetone condensation in gas-phase process under hydrogen flow. This reaction involves the base-acid coupling of acetone to form mesityl oxide, followed by its hydrogenation to methyl isobutyl ketone (MIBK). The novel catalyst 1% wt. n-Pd/n-ZnCr₂O₄ was utilized during gas-phase reaction during production of MIBK. MIBK selectivity was 70-72% at 66-77% acetone conversion at 300-350° C. Diisobutyl ketone (DIBK) was the main by-product, with a total MIBK+DIBK selectivity up to 88%. The prepared catalysts showed stable activity and may be used repeatedly and for a longer period of time.