Carbon-supported Ru catalyst is arguably the most promising applications of Ru catalysts in ammonia synthesis. However, the insufficient stability of Ru/C catalyst greatly limits its applications, and the elimination of surface oxygen species by carbon preactivation has been imagined to be an efficient method for preparing Ru/C catalyst with high stability. However, herein we demonstrate that the presence of some oxygen functional groups in carbon support of Ba-promoted Ru/C catalyst was beneficial not only to the dispersion of Ru particles, but also to the low-temperature hydrogen adsorption. Furthermore, the formation of CO during heat treatment, which was closely related to oxygen groups, enhanced the ammonia synthesis activities of carbon-supported Ru catalyst with Ba promoter. Therefore, Ru catalyst supported on carbon with a large number of surface oxygen groups showed higher activity. Understanding the effect of carbon support surface on the activity and stability of Ru/C provides a basis for the rational design of the optimal carbon-supported metal catalyst for ammonia synthesis and related reactions.

碳负载的Ru催化剂可以说是Ru催化剂在氨合成中最有前途的应用。然而，Ru / C催化剂的不足的稳定性极大地限制了其应用，并且已经认为通过碳预活化消除表面氧物种是制备高稳定性的Ru / C催化剂的有效方法。但是，本文证明了在Ba促进的Ru / C催化剂的碳载体中存在一些氧官能团，不仅有利于Ru颗粒的分散，而且有利于低温氢吸附。此外，在热处理过程中形成的CO与氧基团密切相关，这增强了含Ba助催化剂的碳载Ru催化剂的氨合成活性。所以，负载在具有大量表面氧基团的碳上的Ru催化剂显示出更高的活性。了解碳载体表面对Ru / C活性和稳定性的影响为合理设计用于氨合成及相关反应的最佳碳载体金属催化剂提供了基础。