Catalyst Active Ingredient

Introduction

The most important factor affecting the efficiency of catalytic combustion of exhaust gas is the catalyst active ingredient. It can be seen that the catalyst active ingredient is the core of the catalyst. The principle of catalyst is to rely on the coordination reaction of active ingredient and pollutants to carry out adsorption of pollutants, and then the pollutants are concentrated and efficiently catalyzed into harmless substances. Therefore, the selection of appropriate catalyst active ingredient for air pollution governance caused by industrial exhaust gas and automobile exhaust is very critical.

Classification

The catalyst active ingredient used in the catalysis of industrial exhaust and automobile exhaust can be mainly divided into three categories of precious metals, transition metal oxides and composite oxides.

• Precious metals: Commonly used precious metals include Au, Pt, Ru, Pd, Rh, etc., among which Pt, Pd, Rh as key catalytic elements are most frequently used. At present, Pt and Pd used for automobile exhaust treatment account for more than 50 percent of the total precious metals used in the world, while Rh accounts for more than 80 percent. Precious metal has unfilled d layer electron orbital, moderate strength and its surface is easy to adsorb reactants, which is very conducive to the formation of intermediate active compounds. Therefore, it has excellent catalytic activity with characteristics of low ignition temperature and turning point temperature. That is, once the temperature exceeds a certain point, the catalytic conversion rate will rise linearly, and intermediates are rarely produced.
• Transition metal oxides: The transition metal compounds have good REDOX activity due to strong ability of losing electrons or gaining electrons, which can be used as catalyst active ingredient. At present, manganese, copper, cerium, cobalt, iron, nickel, vanadium, aluminum and other transition metal oxides are often used as the main active ingredients. Transition metal oxides, as the catalyst active ingredient, usually use lattice oxygen to achieve catalytic transformation by metal ion valence change. And gaseous oxygen cannot be adsorbed and supplemented, so transition metal oxides need a higher ignition temperature. However, they have the characteristics of low cost and high activity. Transition metal oxide catalysts are divided into single metal oxide catalysts such as CuO, MnOx and mixed metal oxide catalysts. Mixed metal oxide catalysts have higher catalytic activity and better stability than single metal oxide catalysts.
• Composite oxides: The composite oxides can be divided into perovskite composite oxides and spinel composite oxides. Perovskite composite oxide (ABO₃) has good catalytic activity due to its special structure and properties. Spinel composite oxide (AB₂O₄) is a unique type of crystal structure, belonging to the cubic crystal system. Because of its special structure, it has the advantages of low surface acidity, good thermal stability, good selectivity, low reaction temperature and no by-products. Therefore, it as a catalyst active ingredient has widely used in various catalysis fields.

Our Products

Although there are many substances used as catalyst active ingredient, precious metals have been widely used in atmospheric governance because of their excellent performance. Alfa Chemistry can provide catalyst active ingredient and some of featured products are listed as follows. You can also email, call or online inquiry for more catalyst active ingredient products.

Featured products

Alfa Chemistry is committed to the environmental governance field and focuses on providing comprehensive and high-quality products of catalyst active ingredient. If you can't find the product what you're looking for in our product catalogue, we can also provide you with customized service. Please contact us, if you have any needs.