Synthesizing and utilizing novel nano-crystalline zinc chromite-supported nano-palladium 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 DEG C. The Pd-supported nano-ZnO mixed with different oxides such as Cr2O3, CrO3, MgO, and [gamma]-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 DEG 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.

Description

Technical field [0001] The present disclosure generally relates to the synthesis of a novel nanocrystalline zinc chromite supported nano-palladium catalyst and the use of the novel catalyst to improve the production of methyl isobutyl ketone (MIBK). Background technique [0002] Aldol condensation is an important means to produce carbon-carbon bonds between two aldehyde or ketone molecules in organic synthesis. Aldol products (β-hydroxy aldehydes or β-hydroxy ketones) have hydroxyl and carbonyl functional groups, which can be transformed into various industrial important products such as diols, α, β-unsaturated aldehydes, α , Β-unsaturated ketones, saturated alcohols, allyl alcohols, aldehydes and ketones. However, aldol condensation is a reversible process. In terms of conversion rate, especially when the raw material is ketone, due to the unfavorable balance, this feature limits the utilization of the reaction. Acetone condensation is an example for the synthesis of very impo...

AI Technical Summary

Problems solved by technology

[0005] The production process is complex and expensive to operate

Use of homogeneous liquid base and acid catalysts creates a corrosive environment, requires an additional neutralization process to dispose of it, and creates a significant waste stream

Additionally, the separation of DA and MO is mandatory to implement its sequential steps

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