Copper-cobalt-silicon catalyst used in preparation of lower alcohol from synthetic gas and preparation method thereof

Abstract

The invention discloses a copper-cobalt-silicon catalyst used in preparation of lower alcohol from synthetic gas and a preparation method thereof, relating to a catalyst. The catalyst is shown as CuiCoj-SiO2, wherein i and j refer to atomic mole numbers of Cu and Co respectively; i is more than or equal to o and less than or equal to 3; j is more than or equal to o and less than or equal to 3; and the catalyst consists of the following components in percentage by mass: 0-20 percent of Cu, 5-25 percent of Co and the balance of SiO2. The preparation method comprises the following steps of: adding Cu(NO3)2.3H2O and Co(NO3)2.6H2O into an absolute ethyl alcohol solution into which citric acid monohydrate is dissolved; adding a certain amount of deionized water; dripwise adding tetraethyl orthosilicate; evaporating in a water bath into gel; drying and baking to obtain a catalyst precursor; and raising the temperature in normal-pressure 5 percent H2 / Ar gas current and reducing to obtain a product. The copper-cobalt-silicon catalyst has high catalytic activity and low lower alcohol space time yield; and in particular, the space time yield of a C2<+> alcohol is increased greatly.

Description

technical field [0001] The invention relates to a catalyst, especially a copper-cobalt-silicon catalyst for preparing low-carbon alcohols from synthesis gas and a preparation method thereof. Background technique [0002] With the continuous rise of international oil prices and my country's energy structure rich in coal and low in oil, the national energy development "Eleventh Five-Year Plan" and "Twelfth Five-Year Plan" clearly pointed out that it is necessary to accelerate the development of coal-based alternative energy. The requirements for environmental protection in the process of industrialization have put the clean utilization of coal on the agenda. Low-carbon mixed alcohols are an important part of coal-based clean energy, whether they are used as direct vehicle clean fuels or fuel additives, as well as energy and chemical raw materials. , has broad application prospects. [0003] In recent years, the research work on the synthesis of low-carbon alcohols from syngas...

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Problems solved by technology

The second is the Rh-based catalyst. The loaded Rh catalyst is added with 1 to 2 kinds of transition metal or metal oxide additives. 2 + Oxygenated compounds have good activity and selectivity, and the main product is ethanol, which has stable performance, but is expensive. The reaction produces toxic gas of acetaldehyde and the catalyst is easily destroyed by CO 2 Toxicization, the process of industrialization is relatively slow

The third is anti-sulfur MoS 2 Catalyst with mild operating conditions, sulfur resistance, low water content in the product, C 2 + The alcohol content is relatively high, up to 30% to 70%, and the main products are ethanol and n-propanol, but it has strict requirements on the hydrogen-carbon ratio of the raw material gas, H 2 / CO must be between 1.0 and 1.1. In addition, cobalt as a catalytic promoter is easy to form carbonyl cobalt with CO and lose cobalt, which affects the stability and life of the catalyst.

The fourth is the Co-Cu catalyst, its operating conditions are relatively mild, and the main product C 1 ~C 6 Straight-chain normal alcohols have strong anti-poisoning and anti-aging capabilities, and are considered to be one of the most industrialized catalysts, but their catalytic activity and low-carbon alcohol selectivity are not satisfactory. Therefore, it is necessary to further improve its Catalytic activity and C 2 + Alcohol selectivity is the key to industrialization

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