氨气预处理提高丙烯气相环氧化安全催化性能研究OA

The direct gas-phase epoxidation of propylene with hydrogen is a highly promising novel method for synthesizing propylene oxide(PO).However,existing reaction systems present significant safety hazards,including wide flammability limits due to the coexistence of combustible gases and oxidizers,high risks of fire and explosion,low catalyst activity,and localized hot spots triggered by uncontrollable side reactions.The cur-rent inability to strike a balance between the economic viability and safety of the catalytic reaction severely re-stricts its industrialization.This study employed an ammonia pretreatment technology,resulting in a catalyst with enhanced catalytic activity(CC3H6=5.7%,SPO=93.1%).Ammonia pretreatment facilitated smaller and more uniform noble metal loading,enhanced the surface hydrophobicity of the titanium silicalite-1(TS-1)zeo-lite,and reduced the acidity of the catalyst surface.Consequently,it promoted rapid desorption of PO and ef-fectively mitigated ring-opening isomerization,thereby reducing the fire and explosion risks from uncontrollable side reactions.Meanwhile,ammonia treatment lowered the reaction temperature of the system,decreased the probability of hot spot formation and expanded the safe operating range for combustible gases and oxidizers.