摘要
分别以K2RuO4,Ru(Ac)3和RuCl3为Ru前驱体,制备了Ru/MgO-CeO2催化剂,并运用X射线衍射、X射线荧光光谱,CO吸附、N2物理吸附和H2程序升温还原等技术对催化剂进行了表征,考察了Ru前驱体对Ru/MgO-CeO2催化剂氨合成性能的影响.结果表明,Ru前驱体对载体MgO-CeO2和Ru的还原性能、氯残留量和催化剂比表面积的影响都很大,从而导致催化剂的氨合成性能的不同.其中以K2RuO4为Ru前驱体制备的催化剂的载体和Ru容易还原,无氯离子,且比表面积较高,因而催化剂活性和氨合成转换频率较高.在10MPa,425°C,10000h-1条件下,K2RuO4,Ru(Ac)3和RuCl3作前驱体制备的催化剂上氨合成转换频率比为1.33:1.05:1.
Ru/MgO-CeO2 catalysts were prepared by co-precipitation with different precursors,including K2RuO4,Ru（Ac）3,and RuCl3,the obtained catalysts were characterized by X-ray diffraction,X-ray fluorescence,N2 physisorption,temperature-programmed reduction,and CO chemisorption. The results showed that the ammonia synthesis activity of the Ru/MgO-CeO2 catalyst prepared with K2RuO4 was 16.0% at 10 MPa,450 °C,and 10 000 h-1,which was higher than those obtained with the other two precursors. The turnover frequency （TOF） of the Ru/MgO-CeO2 catalyst prepared with K2RuO4 was higher than those obtained with the other precursors under the same reaction conditions. The influence of precursors and preparation methods on the structure and performance of the catalysts was studied. The ratio of Ru/MgO-CeO2 catalysts prepared with K2RuO4,Ru（Ac）3,and RuCl3 as precursors for ammonia synthesis turnover frequency is 1.33：1.05：1 under 10 MPa,425 °C,and 10 000 h-1.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
2010年第12期1452-1456,共5页
基金
国家自然科学基金(20576021)
国家科技支撑计划(2007BAE08B02)
关键词
前驱体
氨合成
氧化镁
二氧化铈
钌
precursor
ammonia synthesis
magnesium oxide
cerium dioxide
ruthenium
