Highly efficient Ru/MgO–CeO2 catalyst for ammonia synthesis

Ru/MgO–CeO2 catalysts were prepared by using co-precipitation (CP), deposition precipitation (DP) and modified deposition precipitation (MDP) methods. These samples were characterized by XRD, N2 physisorption, H2-TPD, N2-TPD, H2-TPR and CO chemisorption. It is found that the catalytic activity of Ru/MgO–CeO2 prepared by MDP method was 2.5 times higher than that of the catalyst prepared with the DP route under the same reaction conditions. The activity of the catalyst with MDP method was also higher than that of Ru/MgO–CeO2 synthesized by CP method. The possible influence factors of preparation methods on the catalytic performance were proposed based on the experimental results.

Graphical AbstractHighly efficient Ru/MgO–CeO2 was prepared by modified deposition precipitation (MDP) method for ammonia synthesis. Higher catalytic activity was due to high utilization ratio and more suitable particle size of ruthenium, stronger adsorption of nitrogen, and easier reduction of ruthenium and support of MgO–CeO2.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch Highlights► Ru/MgO-CeO2 catalysts were prepared by using co-precipitation, deposition precipitation and modified deposition precipitation. ► Ru/MgO-CeO2 prepared by modified deposition precipitation had more suitable particle size of ruthenium, stronger adsorption of nitrogen, and easier reduction of ruthenium and MgO-CeO2. ► The catalytic activity of Ru/MgO-CeO2 prepared by modified deposition precipitation was much higher than that of the catalyst prepared with the deposition precipitation or co-precipitation.