Compound metal oxide and nitride catalyst for low-temperature selective catalytic reduction of ammonia

Abstract

The present invention relates to 'compound metal oxide and nitride catalyst for low-temperature selective catalytic reduction of ammonia' and pertains to the field of catalysts. In A-B-C compound metal oxide, A is a or multiple kinds of lanthanide series metals, B is a or multiple kinds of transition metals, C is a or multiple kinds of alkaline or alkaline earth metals, A must contain La, and when C content is zero, B is not Co element alone. As proved by experiments, the compound metal oxide of the present invention can obviously raise the conversion rate from NO to NO2. When the oxide contains A, B and C elements, its activity will be higher than that only containing A and B elements. Meanwhile when this compound metal oxide of the present invention is used as a catalyst together with copper and iron molecular sieve, it may realize the function of low-temperature selective catalytic reduction of ammonia, particularly below 200 DEG C, it makes the industrialization of SCR technique simpler and more energy conserving.

Description

technical field [0001] The invention relates to an ammonia selective catalytic reduction nitride catalyst, in particular to a compound metal oxide and a catalyst suitable for nitrogen selective catalytic reduction of nitrogen compounds at low temperature. technical background [0002] Nitrogen oxides (NOx) mainly include N 2 O, NO, N 2 o 3 , NO 2 , N 2 o 4 , N 2 o 5 Compounds such as NOx are the main air pollutants. The total amount of NOx emitted into the atmosphere in the world reaches 50 million tons every year, and it is still growing. Therefore, research on NOx control is one of the main contents in the field of global environmental protection. [0003] There are two ways to produce NOx: one is natural production, and the other is artificial production. Natural sources include lightning, ammonia oxidation in the atmosphere, and nitrification of microorganisms in the soil. The NOx formed in nature has reached an ecological balance due to natural selection, so it...

AI Technical Summary

Problems solved by technology

[0010] Although SCR technology has been industrialized and has some advantages, it still has some disadvantages, such as short catalyst life, low activity of traditional vanadium-based catalysts, high sulfur dioxide oxidation activity, and a lot of sulfate formation. Causes catalyst deactivation and clogs downstream piping

Therefore, it is necessary to put the catalyst after the desulfurization and dust removal equipment, so that the life of the catalyst will be greatly improved; however, generally speaking, after the desulfurization and dust removal equipment, the temperature of the tail gas is reduced below 200 degrees Celsius, and the activity of the traditional vanadium-titanium catalyst lower

In recent years, copper and iron molecular sieve catalysts have been found to have high catalytic activity and nitrogen selectivity [3], but the low-temperature activity of the catalyst is also low, especially when the temperature of the exhaust gas is below 200 degrees Celsius

Images