What is the cause of hopcalite catalyst deactivation and poisoning?

Hopcalite catalyst is a catalyst commonly used in air purification and gas treatment, especially in the process of carbon monoxide (CO) oxidation to carbon dioxide (CO₂). However, in actual use, the hopcalite catalyst may gradually deactivate or "poison", resulting in a decrease in its performance. So, what exactly causes the deactivation and poisoning of the hopcalite catalyst? This article will analyze it from four aspects: temperature, humidity, usage scenarios, and product quality.
1. The influence of temperature
Temperature is one of the key factors affecting the performance of the hopcalite catalyst. Hopcalite catalysts usually work at room temperature or lower temperatures, but if the temperature is too high or too low, it will cause it to deactivate.
High temperature deactivation: When the temperature is too high (usually over 150°C), the active sites of the catalyst may sinter, resulting in a decrease in surface area and decreased activity. In addition, high temperature may also destroy the structure of the catalyst and make it lose its catalytic ability.
Low temperature failure: Under low temperature conditions, the reaction rate of the catalyst will be significantly reduced, resulting in a decrease in CO oxidation efficiency. Although this is not a permanent deactivation, the catalyst may not meet actual needs under low temperature conditions.
2. The influence of humidity
Humidity is another important factor that affects the performance of the hopcalite catalyst. The content of water vapor (H₂O) in the air directly affects the activity of the catalyst.
High humidity environment: In a high humidity environment, water molecules will occupy the active sites of the catalyst, hindering the contact between CO and the catalyst, thereby reducing the catalytic efficiency. In addition, water vapor may react with other pollutants (such as sulfides) to generate acidic substances, further poisoning the catalyst.
Low humidity environment: Although the low humidity environment has less impact on the catalyst, if there are other pollutants (such as oil mist or dust) in the air, low humidity may cause these pollutants to adhere to the catalyst surface more easily, causing blockage.
3. Impact of usage scenarios
The usage scenario of hopcalite catalyst has an important impact on its life and performance. Different usage scenarios may face different pollutants and operating conditions.
Industrial environment: In an industrial environment, the air may contain a large amount of pollutants such as sulfides, nitrogen oxides, and oil mist. These pollutants will react with the catalyst and cause catalyst poisoning. For example, sulfides will react with the active components of the catalyst to generate sulfates, thereby permanently destroying the activity of the catalyst.
Confined space: In confined spaces (such as underground parking lots, mines, etc.), the CO concentration is high and the catalyst workload is large, which can easily lead to rapid deactivation of the catalyst. In addition, the poor air circulation in the confined space may cause abnormal local temperature or humidity, further affecting the performance of the catalyst.
4. Influence of product quality
The quality of the hopcalite catalyst directly determines its ability to resist deactivation and poisoning. Catalysts produced by different manufacturers may differ in terms of active ingredients, carrier materials, preparation processes, etc.
Active ingredient content: The higher the content of the active ingredient (such as copper, manganese, etc.) of the catalyst, the better its catalytic performance is generally. However, if the active ingredient is unevenly distributed or the content is too low, it may cause the catalyst performance to be unstable and easy to deactivate.
Carrier material: The selection of carrier material is crucial to the performance of the catalyst. High-quality carrier materials (such as alumina, silica, etc.) can provide a larger surface area and better stability, thereby improving the catalyst's ability to resist poisoning.
Preparation process: The preparation process of the catalyst (such as calcination temperature, molding method, etc.) will affect its microstructure and the distribution of active sites. If the preparation process is improper, the catalyst structure may be unstable and easy to deactivate.
In order to extend the service life of hopcalite catalyst, it is recommended to control the temperature and humidity in actual application, avoid using it in a heavily polluted environment, and choose high-quality catalyst products. Through scientific use and maintenance, hopcalite catalyst can play its role in purifying air more efficiently.