Preparation and Catalytic Properties of Barium Cerate and Yttrium-Doped Barium Cerate Supported Ruthenium for Ammonia Synthesis

Barium cerate (BaCeO3) and yttrium-doped barium cerate (BaCe0.9Y0.1O3-δ) were synthesized by the citric acid method and used as supports for Ru/BaCeO3 and Ru/BaCe0.9Y0.1O3-δ catalysts prepared by incipient wetness impregnation using Ru3(CO)12 as precursor. The supports and catalysts were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Their catalytic properties for ammonia synthesis were evaluated in a fixed-bed reactor. The stability of BaCeO3 was superior to that of BaCe0.9Y0.1O3-δ, and the catalytic activity of Ru/BaCe0.9Y0.1O3-δ was higher than that of Ru/BaCeO3. The rate of ammonia synthesis over Ru/BaCe0.9Y0.1O3-δ was 432.5 ml/(g·h) at 3.0 MPa, 425 °C, and 15 000 h−1, which was 1.6 times higher than that of Ru/BaCeO3. The electronic interaction between Ce4+ and Ru nanoparticles was the key factor for the difference in catalytic activity and stability. :采用柠檬酸法合成了 BaCeO3 和掺杂 Y3+的 BaCe0.9Y0.1O3-δ 复合氧化物, 以 Ru3(CO)12 为前体, 利用浸渍法制备了 Ru/BaCeO3 和 Ru/BaCe0.9Y0.1O3-δ 催化剂. 通过 X 射线衍射、扫描电镜和透射电镜技术对样品进行了表征, 并在固定床反应器中考察了催化剂的氨合成反应活性. 结果表明, 载体 BaCeO3 的稳定性优于 BaCe0.9Y0.1O3-δ, 但 Ru/BaCe0.9Y0.1O3-δ 催化剂的氨合成活性明显高于 Ru/BaCeO3, 在 3.0 MPa, 15 000 h−1, 425 °C 反应时, Ru/BaCe0.9Y0.1O3-δ 催化剂上氨合成反应速率达到 432.5 ml/(g·h), 是 Ru/BaCeO3 催化剂的 1.6 倍. 这种活性和稳定性的显著差异来自载体中 Ce4+ 与 Ru 纳米粒子间的电子作用.