低温低压氨合成催化剂的制备与催化性能研究

Preparation and Catalytic Performance of the Catalyst for Ammonia Synthesis in Low Temperature and Pressure

以尿素为燃料,采用一步燃烧法制备了钙钛矿型BaZrO3负载钌催化剂,用于催化氨合成反应。研究发现,当尿素用量为理论用量的1.5倍时得到催化剂中BaZrO3物相最纯,催化剂的活性最高。在3 MPa,10000 h-1和425℃条件下,其出口氨浓度和催化反应速率分别可以达到4.81%和270.99 mL/(g.h)。该催化剂的高活性主要是由于载体的强供电子作用和电子传导性能导致的。

The BaZrO3 materials with perovskite style were synthesized by urea - nitrate combustion method and sup- ported Ru to catalytic ammonia synthesis. The effects of urea/nitrate ration on XRD patterns and catalytic performance were investigated. The results showed that when 150% of stoichiometric amount of urea was used, the catalyst exhibited an optimum catalytic behavior. The concentration and activity of NH3 were 4. 81% and 270. 99 mL/（ h·g）, respectively, under the condition of 425℃, 3 MPa and 10000 h- 1, mainly due to the electron conductivity of the its support.