【摘要】 发现钙钛石型复合氧化物LaMnyCo_1-yO₃中B位过渡金属离子Mn,Co之间的相互作用及其氧化还原性能是影响氨氧化反应中NO选择性的重要因素.B位少量掺杂可促进过渡金属离子的氧化还原性,但B位组成相当时时（y=0.5）,则不利于它们的氧化还原.富锰区（y>0.5）,Mn³⁺-O^2--Mn⁴⁺的超交换作用对样品的磁性及NO选择性起决定作用,富钴区（y<0.5）,Co²⁺和Co^Ⅲ离子的存在及其浓度是影响NO选择性的主要因素.y=0.5时样品的结构决定了样品的强铁磁性质,并由于Mn³⁺-O^2--Co³⁺之间不易氧化还原因而对生成NO不利.更多还原

【Abstract】 It has been found that the interaction between the two transition metal Mn, Co ions on B-site and their Redox property are the important factors influencing the NO-selectivity in ammonia oxidation. The NO-selectivity is related to the redox ability of Mn3+→Mn4+ or Co2+→Co3+, which could be promoted by doping a small amount of foreign transition metal ions on B-site of matrix samples, but not for the sample with the composition of y = 0.5. In Mn-rich region (y>0.5), the magnetic property and NO-selectivity are controlled by the ferromagnetic superexchange of Mn3+-O2--Mn4+. The main factor influencing the NO-selectivity of Co-rich samples (y<0.5) is the concentration of Co2+ and CoⅢ ions. The strong ferromagnetism of the sample with the composition of y = 0.5 may be due to its crystal structure, and the redox between Mn3+ and Co3+ is unfavorable for the producing of NO. There exists a close relationship between the NO-selectivity and the valence, d-electron configuration, electron transmission rate and the interaction between the electrons.更多还原