焙烧温度对Ru/Ba-Mg(Al)O4氨合成催化剂性能影响

采用超声-沉淀-强静电吸附法制备了化学性质比较稳定的掺钡纳米镁铝复合氧化物Ba-Mg(Al)O₄，并以其为载体、Ru₃(CO)₁₂为活性组分前驱体，制备了一系列钌基氨合成催化剂。通过场发射扫描电镜、X射线衍射和N2物理吸附等表征手段，重点考察了焙烧温度对载体的物相组成和表面织构的影响。结果表明，随着焙烧温度的升高，制备的载体比表面积逐渐下降，表面碱性增强。当载体焙烧温度为780 ℃时，制备的负载型Ru/Ba-Mg(Al)O₄催化剂表现出较高的催化活性，在425 ℃、10 MPa和10 000 h^-1条件下，出口氨浓度达到49.17 mmol·(g·h)^-1。

Effects of calcination temperature on Ru/Ba-Mg(Al)O4 catalysts for ammonia synthesis

Ba-doped nano-Mg(Al)O₄ supports with steady chemical properties were prepared by chemical precipitation-strong electrical adsorption(SEA) method with the aid of ultrasonic wave.Ru/Ba-Mg(Al)O4 catalysts were prepared by impregnation method using the modified Ba-Mg(Al)O₄ as the supports and 2wt% Ru₃(CO) ₁₂ as the active component.The effects of calcination temperature on surface texture and phase composition of the support were investigated by FE-SEM,X-ray diffraction and N2 physical-adsorption.The results showed that the surface area of the support gradually decreased and the surface basicity enhanced with the increase of calcination temperature.Ru/Ba-Mg(Al)O₄ catalyst prepared with the support calcined at 780 ℃ exhibited higher catalytic activity.The ammonia concentration in outlet was 49.17 mmol·（g·h）^-1 under the condition of 425 ℃,10 MPa and 10 000 h^-1.