Language

SSZ-13 molecular sieve

SSZ-13 molecular sieve has a chabazite (CHA) structure, which is composed of AlO4 and SiO4 tetrahedra connected end to end through oxygen atoms, ordered into an ellipsoidal cage (0.73 nm × 1.2 nm) with an eight-membered ring structure and a three-dimensional Cross-channel structure, pore size is 0.38 nm×0.38 nm, and its specific surface area can reach 700 m2/g. Since SSZ-13 has the characteristics of ordered pore structure, good hydrothermal stability, more surface proton acidic centers and exchangeable cations, it is widely used in automobile exhaust NOX removal, methanol to olefins (MTO) and CO2 adsorption. Excellent performance in separation.

Categories：

Material Chemistry

Email：sale06@alfachem.cn

Inquiry

Chat Now

Product introduction

Removal of NOX from automobile exhaust

NOX is one of the main pollutants in automobile exhaust, which brings great harm to the atmospheric environment and human health. For NOX emission control, gasoline vehicles mainly use three-way catalysts to simultaneously purify CO, HC, and NOX. The combustion mode of diesel vehicles is different from that of gasoline vehicles. The oxygen content in the exhaust gas is extremely high. Under such lean combustion conditions, the reduction of NOX is extremely difficult. The catalytic reduction of NOX in diesel vehicles cannot be achieved through a three-way catalyst. Therefore, the development of new catalysts has attracted worldwide attention
country's attention.

In recent years, studies have found that SSZ-13 molecular sieve is a good carrier. After loading various metal ions on it, it has good activity in the selective catalytic reduction (SCR) of NOX, showing broad application prospects and good performance. development potential.

Methanol to olefins

CHA type molecular sieve with microporous structure has good selectivity for low carbon olefins, and the geometric configuration of the molecular sieve plays a decisive role. The cage size of SSZ-13 is large, and its size determines the type of cage intermediate products. The pore size of SSZ-13 molecular sieve just meets the production of the intermediate product polymethylbenzene required to generate low-carbon olefins, so SSZ-13 shows good selectivity to low-carbon olefins.

Gas separation

There are not only molecular sieve channels in the SSZ-13 molecular sieve membrane, but also non-molecular sieve channels that are larger than the molecular sieve channel pore diameter (3.8Å). Molecular sieve membrane has good separation performance for CO2/CH4, H2/CH4, CO2/N2 and H2/n-C4H10, so SSZ-13 molecular sieve membrane has good separation ability for gas phase small molecules.

The R&D center experiments concluded that the reasons why SSZ-13 molecular sieve has better separation performance are: ① The micropores of the molecular sieve limit the diffusion of molecules;

② The pore window of the molecular sieve is just suitable for adsorbing CO2, and during the ion exchange process, eight The ring window will not be occupied by exchange ions;

③ The adsorption sites have different electrostatic adsorption for different gases.

Key words: