Application of zeolite molecular sieve in the field of catalysis

Application of zeolite molecular sieve in the field of catalysis Zeolite molecular sieve has a complex and changeable structure and unique pore system, which is a kind of catalyst with excellent performance. ZSM-5 and Y-type zeolite molecular sieve are used together in FCC reaction to obtain higher yield of gasoline, propylene and butene. MCM-22 zeolite molecular sieve has significant advantages in the alkylation reaction. For example, MCM-22 is used as a liquid-phase alkylation catalyst to catalyze the reaction of benzene and ethylene to produce ethylbenzene. With high stability and low dosage, it can be regenerated in-situ in the reactor, while other types of catalysts must be taken out of the reactor to be regenerated. In the synthesis reaction of short-chain alkyl substituted aromatics, MCM-56 has better activity and is not easy to deactivate. ZSM-22 is used as a catalyst in many processes, but it is mainly used for two aspects: butene skeletal isomerization and n-heptane isomerization. The main applications of molecular sieves as catalysts are shown in the table below Table 1 Examples of main molecular sieve catalysts Catalytic process Type of catalyst Example of catalyst Petroleum catalytic cracking, solid acid, rare earth-Y molecular sieve, ultra-stable-Y molecular sieve Hydrocracking dual-function palladium-ultra-stable Y-type molecular sieve, molybdenum-nickel ultra-stable Y-type molecular sieve Tungsten-nickel super stable Y-type molecular sieve C5 and C6 alkane isomerization dual function platinum-mordenite Diesel or lubricating oil with hydrogen and pour point reduction dual function, shape selective Palladium-mordenite, palladium-zinc-ZSM-5 molecular sieve Selective reforming dual function, shape selective palladium-erionite, chabazite Xylene Isomerization Dual-function, shape-selective platinum-mordenite Toluene disproportionation, solid acid, shape selective mordenite, ZSM-5 molecular sieve Alkylation (synthesis of ethylbenzene) Solid acid, shape selective ZSM-5 molecular sieve Methanol synthesis gasoline Solid acid, shape selective ZSM-5 molecular sieve