Micro-spherical silicon oxide/aluminum oxide based noble metal catalyst and preparation method thereof

Abstract

The invention provides a micro-spherical SiO2-Al2O3 based noble metal catalyst and a preparation method thereof. The preparation method comprises the following steps: dispersing silica sol into a silica sol system, so that silica sol is mixed with alumina sol and a coagulant to form formed sol, forming the sol by virtue of an atomizing dispersion-oil column formation method, and carrying out aging, washing, drying and roasting to obtain micro-spherical SiO2-Al2O3; and loading noble metal active components with the micro-spherical SiO2-Al2O3 as a carrier, obtain the micro-spherical SiO2-Al2O3 based noble metal catalyst. The catalyst has the characteristics that the specific surface area and the pore volume are large, the dispersity of active components is high, the abrasion index is relatively low, and the wear resistance is high. The catalyst is mainly applied to a hydrogenation process of preparing hydrogen peroxide by using a fluidized bed anthraquinone method and has relatively high catalytic activity, selectivity and stability. The catalyst can be also applied to reaction processes such as hydrorefining, selective hydrogenation and selective oxidation in petrochemical engineering and fine chemical engineering production.

Description

[0001] Field [0002] The invention relates to the field of catalyst preparation, in particular to a catalyst for the hydrogenation process of preparing hydrogen peroxide by a fluidized bed anthraquinone method. Background technique [0003] The fluidized bed process is widely used in gas-solid, liquid-solid and gas-liquid-solid phase reaction processes in chemical industry, petroleum, energy, environmental protection and metallurgy. This process has the advantages of less catalyst addition, excellent mass transfer performance and reactant conversion efficiency. High advantages, fluidized bed reactor and fluidized bed process are the most ideal for reactions with high requirements on gas-liquid flux, production capacity and reaction speed, especially for reactions with strong exotherm and need to keep the reactor temperature stable Therefore, in some important reaction processes, it has become a trend to replace the original fixed bed process with fluidized bed process. [00...

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Problems solved by technology

The results show that the silicon-containing alumina prepared by this method has a large specific surface area and concentrated pore distribution, but the silicon-alumina bond is weak after simple mechanical mixing, resulting in poor sample stability, because its silicon source is sodium silicate, in order to ensure that the product With low sodium content, the washing process will generate a lot of waste water

Liang et al. studied impregnation loading SiO in Study on Production Technology of Isobutane Dehydrogenation Fluid Catalyst (Catal.Commun.2007,4,131-136). 2 For Microspherical K 2 O-CrO x / Al 2 o 3 The influence of catalyst surface properties and catalytic activity, the results show that supported SiO 2 Afterwards, the stability of the catalyst is enhanced, but the catalytic activity is reduced, the reason is that the impregnation method supported SiO 2 clogged al 2 o 3 Part of the pores of the carrier leads to a decrease in the specific surface, which affects the active component CrO x The degree of dispersion, which affects its catalytic activity

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