摘要
四种国产活性炭既作为载体又作为还原剂被用于ＮＯ还原反应．山楂核炭和山桃核炭作载体时ＮＯ还原转化率很高，椰壳炭和煤质炭作载体时ＮＯ还原转化率则较低．四种活性炭两－两分组现象可由其元素分析、ＮＨ３－ＴＰＤ、还原性及ＮＯ吸附量等结果来解释．另外ＣｕＯ／椰壳炭与ＣｕＯ／煤质炭的ＮＯ还原转化率的差别主要归因于二者的ＮＯ吸附量不同．对ＣｕＯ／山楂核炭和ＣｕＯ／山桃核炭，ＮＯ还原转化率随反应温度的相对变化主要由其还原性和Ｃｕ（Ⅱ）的分散度决定．由此推断出在４００℃以下时，ＮＯ（ａ）→Ｎ（ａ）＋Ｏ（ａ）是速控步骤，４００℃以上时，Ｃ＋２Ｏ（ａ）→ＣＯ２是速控步骤．
our kinds of active carbon (AC), which were made from coconut shell (CS), hawthorn nut (HN), mountain peach nut (PN) and coal (C) respec tively, were used in the reduction of NO as both support and reducing agent. It was found that the conversion of NO was different on different kinds of active carbon, i. e. CuO/HNAC and CuO/PNAC gave comparatively higher conversion of NO; however, the conversion was lower over CuO/CSAC andCuO/CAC. This great disparity was well concerned with their elemental composition? NH3-TPD results, reducing ability and amount of adsorbed NO. In addition, the dispersion of Cu(Ⅱ) on active carbons had also a greatinfluence on NO reduction. It was demonstrated that the higher NO conversion below 400℃ on Cuo/HNAC was due to its better dispersion of Cu(Ⅱ)than CuO/ PNAC. In contrast, the reducing ability of the supports became aleading factor of C and NO reaction over CuO/HNAC and CuO/PNAC above 400℃ Therefore, it was concluded that NO(a)→N (a) +O(a) is a ratelimiting step below 400℃, however, C+2O (a)→CO2 become rate-limiting foroverall reaction C+ 2NO→CO2+N2 at above 400℃.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
1996年第2期117-122,共6页
基金
全国博士后流动站科研经费资助
中国博士后科学基金
