We investigated the kinetics of NH₃ synthesis over a catalyst consisting of low-crystalline Ru nano-layers supported on Pr₂O₃. We determined the reaction orders with respect to N₂, H₂, and NH₃ at various temperatures and pressures over Ru/Pr₂O₃, as well as Ru/CeO₂ and Ru/MgO. The reaction orders with respect to N₂ were always almost unity for all the catalysts under all the reaction conditions, indicating that the rate-determining step was NN bond cleavage. In contrast, the reaction orders with respect to H₂ differed among the catalysts and decreased with increasing pressure and increased with increasing temperature. Under all conditions, the reaction order with respect to H₂ was largest over Ru/Pr₂O₃ and smallest over Ru/MgO, indicating that hydrogen poisoning of the Ru surface was retarded to a greater extent over Ru/Pr₂O₃ than over Ru/MgO. In agreement with the trends of the H₂ reaction orders, the NH₃ synthesis rates over Ru/Pr₂O₃ at 400 °C rose drastically (64 mmol h⁻¹ g⁻¹) as the pressure was increased from 0.1 to 3.0 MPa. Furthermore, decreasing the feed gas H₂/N₂ ratio at 3.0 MPa effectively increased the NH₃ synthesis rate over Ru/Pr₂O₃, which reached 45 mmol h⁻¹ g⁻¹ at 350 °C at a H₂/N₂ ratio of 1/0.5.

我们研究了由负载在Pr ₂ O ₃上的低结晶Ru纳米层组成的催化剂上NH ₃合成的动力学。我们确定了在Ru / Pr ₂ O ₃以及Ru / CeO ₂和Ru / MgO上的各种温度和压力下，关于N ₂，H ₂和NH ₃的反应顺序。对于所有催化剂，在所有反应条件下，相对于N ₂的反应阶次几乎总是统一的，这表明速率确定步骤是N N键断裂。相反，关于H ₂的反应阶数催化剂之间存在差异，并且随着压力的增加而降低，并且随着温度的升高而增加。在所有条件下，相对于H ₂的反应顺序在Ru / Pr ₂ O _3上最大，而在Ru / MgO上最小，这表明Ru表面的氢中毒在Ru / Pr ₂ O _3上比在Ru / Pr ₂ O ₃上受到更大程度的抑制。超过Ru / MgO。与H ₂反应顺序的趋势一致，在400°C的条件下，Ru / Pr ₂ O ₃上的NH ₃合成速率急剧增加（64 mmol h ^-1  g ^-1当压力从0.1 MPa增加到3.0 MPa时）。此外，在3.0 MPa下降低进料气H ₂ / N ₂比可有效提高NH _3的合成速率（相对于Ru / Pr ₂ O _3），后者在350°C的H ₂ / N下达到45 mmol h ^-1  g ^-1 ₂比为1 / 0.5。