Preparation method and denitrification application of a mesoscale-regulated multi-level core-shell structure bimetallic mof-74(co-cu)

Abstract

The invention provides a preparation method and denitrification application of mesoscale-controlled multi-level core-shell structure bimetallic MOF-74 (Co-Cu). The catalyst selects cobalt-containing long-chain organic molecular salts and organic ligands for high-efficiency coordination, and performs special surface treatment on them, and then undergoes crystal post-synthesis modification in a low-temperature steam environment to make Cu metal nanoparticles modified by surfactants Multi-level core-shell structure composites with different thicknesses are self-grown on the surface of the Co precursor, and the prepared catalyst has a large specific surface area, good dispersion, and high selectivity. The catalyst prepared by the invention has excellent low-temperature catalytic denitrification activity, and the conversion rate of nitrogen oxides in the operating window of 200-275°C reaches over 96%.

Description

technical field [0001] The invention relates to a preparation method of a novel multi-level core-shell structure MOF-74 (Co-Cu) material with excellent low-temperature CO selective catalytic reduction NO (CO-SCR) performance. It belongs to the field of new material design and preparation, and also involves its practical application as a catalytic material in low-temperature flue gas denitrification. Background technique [0002] Nitrogen oxides (NOx) from fossil fuel combustion are currently considered a major source of air pollution, causing various health and environment-related problems such as photochemical smog, acid rain, ozone depletion, and the greenhouse effect. Selective catalytic reduction technology is the most widely used and most effective means of denitrification in coal-fired power plants. Traditional NH 3 -In the SCR reaction, the reducing agent NH 3 Large consumption, easy to corrode equipment, and produce secondary pollutants. In addition, CO is produc...

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Problems solved by technology

However, in the conventional synthesis methods currently reported, the efficiency is usually low in a solvent environment.

The researchers also found that inorganic metal salts of Co such as Co(NO 3 ) 2 ·6H 2 O,CoCl 2 ·6H 2 O,Co(CH 3 COO) 2 4H 2 O is used as a raw material to prepare Co precursors. Experimental studies have found that inorganic salts tend to lead to low deprotonation rates during the reaction process, thereby limiting the coordination efficiency of metals and organic ligands, affecting the synthesis rate of Co precursors, and making bimetallic MOFs materials. The synthesis is difficult and the yield is low

And in previous studies, metal nanoparticles are prone to agglomeration, which reduces the surface area and active sites, thereby reducing the catalytic activity.

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