An organic electron-transport compound for phosphorescent OLEDs is reported, which possesses the advantages of low molecular weight, enhanced glass transition temperature and electron mobility upon doping with 8-hydroxyquinolatolithium (Liq) as well as facile synthesis and purification. The analytically pure NaAN-m-TRZ (m/z = 611.73) is obtained through coupling the 4,6-diphenyl-1,3,5-triazin-2-yl unit via a 1,3-phenylene linker with 10-(naphth-2-yl)-anthracen-9-yl moiety. The residual bromo intermediate could be easily removed by column chromatography and/or recrystallization from CH2Cl2, hence eliminating a high-risk factor for OLED stability. Thermal analyses show that it exhibits a Tg of 157 ℃ and decomposition temperature of 353 ℃ at 1% weight loss. NaAN-m-TRZ has a HOMO level of -5.76 eV determined by the ultraviolet photoelectron spectroscopy measurement and an estimated LUMO level of -2.84 eV. Doping NaAN-m-TRZ with 50% (mass fraction) Liq yields impressive electron mobility of 6.23×10-5~7.19×10-4 cm2·V-1·s-1 @ E = (2~5)×105 V·cm-1 using space-charge-limited current model, which contributes to suppressing triplet-polaron annihilation in the phosphorescent OLEDs. Consequently, based on the single NaAN-m-TRZ∶Liq electron-transport layer, the top-emission green phosphorescent OLED involving Ir(ppy)2(m-mbppy) produces extraordinary durability with projected lifetime t97 of 2 567 h @ 1 000 cd·m-2 as well as a luminous efficiency of 72.2 cd·A-1 and power efficiency of 81 lm·W-1@ 1 000 cd·m-2.