1. Principle of DeNOx Catalyst
DeNOx catalyst is mainly used to catalyze the reduction of NOx to nitrogen (N2) and water (H2O), a process called selective catalytic reduction (SCR). Its basic principle involves the following key steps:

Reductant injection: Commonly used reductants include ammonia (NH3) and urea (CO(NH2)2). These reductants are uniformly injected into the flue gas containing NOx in a specific way.
Uniform mixing: The injected reductant needs to be fully mixed with the NOx in the flue gas to ensure the efficiency and effect of the subsequent catalytic reaction.
Catalytic reaction: The mixed flue gas and reductant flow through the DeNOx catalyst layer. Under the action of the catalyst, NOx reacts with the reductant and is reduced to N2 and H2O. The catalyst is usually made of materials such as vanadium titanate, tungstic acid or molybdate, which can effectively promote the reaction and reduce the temperature and energy required for the reaction.
Reaction equations: The main chemical reaction equations are as follows:
4NO+4NH3+O2→4N2+6H2O4NO+4NH3+O2​→4N2​+6H2​O

2NO2+4NH3+O2→3N2+6H2O2NO2​+4NH3​+O2​→3N2​+6H2​O

These equations show that NOx is converted into harmless nitrogen and water under the action of catalysts and reductants.

Control and optimization: In order to ensure the stable operation of the SCR system and the efficient denitrification effect, the system needs to be accurately controlled and optimized. This includes real-time monitoring and adjustment of the flue gas temperature, flow rate, dosage of reductant and the state of the catalyst.

2. How to choose a denitrification catalyst
Choosing a suitable SCR denitrification catalyst is crucial to ensure the performance and efficiency of the SCR system. Here are some key selection factors:

Catalyst activity: The activity of a catalyst determines its ability to catalyze NOx reduction reactions. Highly active catalysts can achieve higher NOx conversion rates at lower temperatures. Therefore, when selecting catalysts, materials with high activity should be given priority.
Selectivity: Selectivity refers to the ability of a catalyst to inhibit other possible reactions (such as ammonia oxidation) when catalyzing NOx reduction reactions. Highly selective catalysts can reduce the formation of by-products and improve denitrification efficiency.
Stability: The stability of a catalyst refers to its ability to maintain its activity and selectivity during long-term operation. Catalysts with good stability can resist the impact of harmful substances in flue gas on its performance and extend its service life.
Toxicity resistance: There may be some substances in flue gas that are toxic to the catalyst, such as arsenic, alkali metals, etc. Selecting a catalyst with good toxicity resistance can reduce the impact of these substances on the performance of the catalyst.
Mechanical strength: The catalyst needs to have a certain mechanical strength to resist physical damage caused by flue gas flow and temperature changes.
Cost-effectiveness: When selecting a catalyst, its cost-effectiveness also needs to be considered. High-performance catalysts are often more expensive, but in the long run, due to their high efficiency and stability, they may bring lower operating costs.
Supplier reputation and technical support: Choosing a supplier with good reputation and strong technical support can ensure the quality and stability of catalyst supply, while providing necessary technical support and after-sales service.