Abstract: Ruthenium/activated charcoal (Ru/AC) treated with synthesized nano-ZnO (n-ZnO) is used for the first time as a novel composite catalyst in one-step self-condensation of acetone (DMK) to methyl isobutyl ketone in the gas phase. The DMK self-condensation was performed under atmospheric pressure, in a tubular glass fixed-bed microreactor, under DMK and H2 continuous flow at temperature in the range of 523 to 648 K. Addition of n-ZnO to Ru/AC resulted in a pronounced increase in the degree of dispersion of Ru and in the acidic/basic sites concentration ratio. For the one-step synthesis of MIBK at 623 K, the composite catalyst with 2.5 wt % Ru loading was an active and selective bi-functional composite catalyst with balanced acid/base and hydrogenation properties. At 523 K, isopropyl alcohol, product of DMK-direct hydrogenation, was produced in high selectivity for instantly investigated composite catalyst.

Abstract: 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 ?-Al2O3 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.