Method for synthesizing methanol at low temperatures

Abstract

The invention discloses a method for synthesizing methanol at the low temperatures, and relates to methanol synthesis. The method includes carrying out heating pretreatment on catalysts in reducing gas atmosphere; cooling the catalysts until the temperatures of the catalysts reach the room temperature, then switching the catalysts into carbon dioxide and hydrogen mixed atmosphere and carrying outreaction for preparing the methanol by means of carbon dioxide hydrogenation. The method has the advantages that the excellent catalytic performance for preparing the methanol by means of carbon dioxide hydrogenation is displayed, conditions are mild, and products are high in selectivity; the CO2 conversion rate can reach 15% under low-temperature reaction conditions, and the selectivity of the methanol can reach 90% at least under the low-temperature reaction conditions; the catalysts are sulfide or metal oxide or supported catalysts with the sulfide or the metal oxide, sintering phenomena can be prevented in reaction procedures, and the stability of the catalysts can be improved; the catalysts are pretreated in the reducing atmosphere, active sites of the catalysts can be positioned in unsaturated coordination environments to a certain extent, accordingly, the catalysts are high in carbon dioxide activation ability, and selective generation of the methanol can be promoted; proceduresfor preparing the catalysts are simple and controllable, and expanded preparation can be facilitated.

Description

technical field [0001] The invention relates to the synthesis of methanol, in particular to a method for synthesizing methanol at low temperature by using a catalyst treated in a reducing atmosphere to carry out hydrogenation of carbon dioxide to produce methanol. Background technique [0002] CO 2 It is one of the culprits of global warming. As an extremely chemically inert substance, it is difficult to be activated at low temperatures. Methanol is considered CO 2 The ideal product of hydrogenation can be used as hydrogen storage material or chemical raw material. However, via CO 2 Hydrogenation of methanol is limited by many factors: at high temperature, CO 2 The reaction of hydrogenation to methanol is thermodynamically unfavorable and accompanied by severe reverse water gas shift (RWGS) side reactions, resulting in the production of large CO by-products; at low temperatures, CO 2 difficult to be activated. For a long time, Cu-based catalysts have been considered as...

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Problems solved by technology

[0003] Some recent reports employ non-Cu catalysts for CO 2 Hydrogenation reaction results, such as In 2 o 3 (Martin et al., Angew. Chem. Int. Ed. 2016, 55, 1–6), ZnO-ZrO 2 (Wangetal, Science Advances2017, 3:e1701290), etc., have improved to a certain extent in terms of catalytic performance, especially catalyst stability, but the high methanol selectivity of these catalysts is only obtained at high space velocity

In addition, the reaction temperature is limited, and it is only catalytically active at high temperatures (above 300 degrees)

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