以2.5% Ru/CeO₂-NR为母体,通过浸渍法制备不同助剂负载的钌基催化剂X-2.5% Ru/CeO₂-NR(X分别为4% K、4% Ba、4% Cs、2% K 2% Ba、2% K 2% Cs、2% Ba 2% Cs),并在温和条件下对其进行了氨合成性能测试。结果表明,不同的助剂组成对催化剂的促进作用大小顺序为:电子(4% Cs)≥电子+结构(2% Ba 2% Cs)>电子+电子(2% K 2% Cs)>结构(4% Ba);其中,4% Cs-2.5% Ru/CeO₂-NR展示了最佳的氨合成性能,在1 MPa、400℃、H₂/N₂体积比为1的条件下氨产率可达16 500 μmol/(g·h),该产率与1 MPa、450℃、H₂/N₂体积比为3条件下的氨产率相当。测试结果表明,适宜的反应参数、Ru⁰质量分数及Ce³⁺/Ce⁴⁺比是钌基氨合成催化剂具有较高催化性能的关键。

Using 2.5% Ru/CeO₂-NR as matrix,ruthenium-based catalysts X-2.5% Ru/CeO₂-NR loaded with different promoters are prepared via the impregnation method (X=4% K,4% Ba,4% Cs,2% K+2% Ba,2% K+2% Cs,and 2% Ba+2% Cs,respectively).Their performance in ammonia synthesis is tested under mild conditions.Experimental results show that the promoting effects of different promoters on the catalysts are in the following order:electron (4% Cs)≥electron+structure (2% Ba+2% Cs)>electron+electron (2% K+2% Cs)>structure (4% Ba).Among them,4% Cs-2.5% Ru/CeO₂-NR displays the best performance in ammonia synthesis,over which the yield of ammonia can reach 16 500 μmol·g^-1·h^-1 under the conditions of 1 MPa,400℃ and v(H₂)/v(N₂)=1. The yield is equal to that under the conditions of 1 MPa,450℃ and v(H₂)/v(N₂)=3. The test results exhibit that the suitable reaction parameters,the content of Ru⁰ and the ratio of Ce³⁺/Ce⁴⁺ are the keys to the high catalytic performance of ruthenium-based catalysts in ammonia synthesis.

张江涛(1997-),男,硕士研究生,研究方向为钌基催化剂合成氨,1348748336@qq.com。