Highly-effectively copper-based catalyst for decomposing methanol to produce hydrogen

Abstract

The invention discloses a highly-effective copper-based catalyst for decomposing methanol to produce hydrogen. The highly-effective copper-based catalyst is a mixture of, based on the weight, 10-60% of CuO, 10-60% of ZnO, 5-50% of Al2O3 and 1-10% of MxOY, wherein alkaline-earth metal M is selected from one of Mg, Ca, Ce and Sr. An adopted preparation method comprises the following steps: (1) modifying alumina carriers by adding the alkaline-earth metal to prepare Al-M modified carriers; (2) adding low-molecular alcohol into mother liquid of the modified carriers, then adding active-metal saltsolution and an alkaline precipitation agent to carry out precipitating reaction, carrying out solid-liquid separation, washing, drying and roasting after the reaction is ended to prepare the catalyst. The highly-effectively copper-based catalyst prepared by the preparation method not only is high in catalytic activity, wide in reaction temperature area and good in low-temperature activity, but also is good in selectivity, fewer in side product and long in service life.

Description

technical field [0001] The invention relates to the technical field of hydrogen production by methanol decomposition, in particular to an efficient copper-based catalyst for hydrogen production by methanol decomposition. Background technique [0002] Hydrogen production by methanol decomposition is a relatively economical hydrogen production method. The reaction process couples the endothermic methanol decomposition reaction and the exothermic carbon monoxide shift reaction, which not only overcomes the danger that the catalyst may be sintered, but also solves the need for external Defects that provide more energy. [0003] The core of methanol hydrogen production technology is the catalyst. At present, the methanol decomposition hydrogen production catalyst widely used in industry is Cu-based catalyst. This type of catalyst has relative advantages in terms of methanol conversion activity, reaction selectivity, operating temperature and raw material cost. . However, Cu-bas...

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Problems solved by technology

However, Cu-based catalysts still have the following disadvantages: (1) The reaction temperature zone of the catalyst is relatively narrow, and the optimum active zone is 260°C-280°C; the reaction temperature is too low, and the activity is poor; the reaction temperature is too high, and the Cu grains in the catalyst grow. The speed is fast, causing the stability of the catalyst to deteriorate and the life-span to be short; (2) Cu-Zn-Al catalyst selectivity is not good, mainly due to ZnO and Al 2 o 3 All belong to amphoteric compounds, which are easy to form acid centers under the influence of various conditions; according to literature reports, the incompletely coordinated aluminum atoms on the surface are connected to form acid centers, which can convert methanol to form hydrocarbons and other by-products; (3) residual sodium content in the catalyst High, affecting catalyst activity

[0008] The active temperature range and selectivity of the catalyst prepared by the above method still need to be further improved

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