Cobalt-based catalyst as well as preparation method and application thereof

Abstract

The invention provides a cobalt-based catalyst as well as a preparation method and application thereof. The invention relates to preparation and application of a cobalt-doped CaTiO3 type catalyst taking a perovskite type composite oxide as a precursor. The molecular formula of the catalyst is Ca < 1-x > LaxTi < 1-x > CoxO3 and Ca < 1-x > AxTi < 1-alpha-beta > Co < alpha > B < beta > O3 (alpha + beta = x), a series of perovskite oxide catalysts are prepared through a citric acid complexation method, metal cobalt or other metals are separated out after reduction treatment, and the perovskite structure is still kept complete; by regulating and controlling the cobalt doping amount or the relative variable of the alloy, the catalyst is used for the reaction for preparing the low-carbon alcohol through carbon monoxide hydrogenation, and the catalyst has high low-carbon alcohol selectivity and good catalytic activity and stability.

Description

technical field [0001] The invention relates to a cobalt-based catalyst, a preparation method and application thereof; it is a novel cobalt-doped CaTiO with a perovskite-type composite oxide as a precursor 3 The preparation and application of the metal catalyst, which is applied to the hydrogenation of carbon monoxide to prepare low-carbon alcohols, belongs to the application field of metal catalysts. Background technique [0002] Syngas is mainly composed of carbon monoxide and hydrogen, and can be obtained from shale gas, coal, biomass, carbon dioxide and carbon-containing wastes. important raw material for energy [1,2] . Due to the continuous consumption of crude oil resources, the increasing demand for chemicals, and the urgent requirement to achieve "carbon neutrality and carbon peaking", syngas conversion has attracted more and more researchers' attention. [1] . Among them, synthesis gas hydrogenation to produce low-carbon alcohols has become one of the key researc...

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Problems solved by technology

[0004] Since the synthesis of low-carbon alcohols from synthesis gas was proposed in the last century, there are mainly four types of catalysts commonly used, but they all have different defects: 1. Rh-based catalysts: noble metal Rh shows the best activity and alcohol selectivity, especially ethanol has become one of them. The main product, but low reserves and high price are common problems of precious metals, and it is easy to sinter during the reaction process, so the application prospect is small [5] 2. Mo-based catalysts: Compared with Rh-based catalysts, Mo-based catalysts have good anti-carbon deposition and anti-sulfur properties, which saves a huge desulfurization investment and also has a good conversion rate, but the catalyst water gas The change activity is high, the carbon dioxide in the product is more, and the reaction conditions are relatively harsh, Mo 2 The loss of sulfur components in S-based catalysts can also cause pollution problems [4,6] ; 3. Modified methanol synthesis catalyst: This type of catalyst mainly includes metals such as Cu, Zn, and Cr, such as Cu-Zn-based and Zn-Cr-based catalysts. This type of catalyst is mainly modified by adding other metal additives. However, the reaction temperature and operating pressure are relatively high, methanol and isobutanol are still the main products, and the selectivity needs to be improved. [7,8] ; 4. Modified Fischer-Tropsch synthesis catalyst: Commonly used active metals include: Fe, Co, Ni. The modified Fischer-Tropsch synthesis catalyst can obtain higher conversion rate and selectivity under mild conditions, but there are bimetallic Phase separation leads to poor stability. Although the products are mainly methane and hydrocarbons, it is also considered to be the most promising type of catalyst. [4,9]

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