Ru和Ce0.8Pr0.2O2载体之间界面调控对氨合成催化剂活性的影响(英文)

Effect of Interface Regulation Between Ru and the Ce_(0.8)Pr_(0.2)O_2 Support on the Activity of Ammonia Synthesis

我们报道了稀土离子掺杂进CeO_2的形貌和不同晶面对氨合成活性的影响.我们采用了将Pr掺杂到CeO_2的晶格里,制备成不同形貌的Ce_(0.8)Pr_(0.2)O_2载体(棒状,立方块).实验表明,在400℃,1 MPa下,Ru/r-Ce_(0.8)Pr_(0.2)O_2催化剂的氨合成催化活性(2 297.09 umol/(g·h))比Ru/c-Ce_(0.8)Pr_(0.2)O_2催化剂的氨合成活性(887.57 umol/(g·h))要高.另外我们发现Cs可以有效的促进氨合成催化剂的活性,如2Cs-Ru/r-Ce_(0.8)Pr_(0.2)O_2(13 698μmol/(g·h)),2Cs-Ru/c-Ce_(0.8)Pr_(0.2)O_2((7 667.7μmol/(g·h)).从本研究可以看出,催化剂的催化活性与载体所暴露的不同晶面有关.

Two Pr-doped ceria nanocrystals with different morphologies( nanocubes and nanorods) were synthesized and used as supports to evaluate the effect of the interface regulation by Pr ions on the structure-sensitive ammonia synthesis reaction activity. The Ru/r-Ce_(0.8)Pr_(0.2)O_2 has a higher activity( 2 297.1 μmol/( g·h)) than that of Ru/c-Ce_(0.8)Pr_(0.2)O_2( 887.6μmol/( g·h)) under the reaction condition of 400 ℃ and 1 MPa. In addition,the promoter Cs can effectively enhance the catalytic activity of catalysts such as 2 Cs-Ru/r-Ce_(0.8)Pr_(0.2)O_2( 13 698.6 μmol/( g·h)) and 2 Cs-Ru/c-Ce_(0.8)Pr_(0.2)O_2( 7 667.7μmol/( g·h)). The effect of the plane of Ce_(0.8)Pr_(0.2)O_2 support on the catalytic performance of Ru/Ce_(0.8)Pr_(0.2)O_2 and 2 CsRu/Ce_(0.8)Pr_(0.2)O_2 catalysts could be correlated to the Pr doping into CeO 2 altered the interface properties( composition and electron structure) between the Ru nanoparticles and the Ce_(0.8)Pr_(0.2)O_2 support.