Design of alkali salt supported gasification catalyst and combustion of particulate in the exhaust gas from diesel engine

碱盐负载气化催化剂设计及柴油机废气颗粒物燃烧

基本信息

批准号：
10555281
负责人：
MOCHIDA Isao
金额：
$ 8.06万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2001
项目状态：
已结题

项目摘要

Catalytic activity of alkali metal carbonates was studied for the combustion of activated carbon grains at 673-773 K by supporting the carbonates on carbon, almina, and a perovskite-type oxide (La_<0.8> Sr_<0.2> Cr_<0.5> Mn_<0.45> Pt_<0.05> O_3, LSCMP). Catalytic activity of V_2O_5/γ -Al_2O_3 as a typical transition metal oxide catalyst was also measured for comparison. Potassium carbonate supported on the carbon exhibited the largest initial rate of the combustion among the catalysts at 723 K, while the achieved conversion within 3h increased almost proportional to the ratio of alkali metal to carbon. V_2O_5γ-Al_2O_3 also showed linear increase of achieved conversion with the amount of catalyst, although the slope was much smaller, indicating that the catalytic turnover number is limited. In contrast, the carbonate supported on LSCMP showed high conversion at an alkali metal to carbon ratio as low as 0.012, indicating a very large catalytic turnover number while the initial activity was comparable to that of the same salts on carbon. However, the carbonate supported on γ-Al_2O_3 and LSCMP alone showed very limited activity. The carbonate supported on LSCMP showed higher activity than carbonates supported on carbon at 673 K. The alkali carbonate seems to be active at lower temperatures on LSCMP. The activities of other alkali carbonates were also measured to examine the role of LSCMP support. Results are discussed from the view point of the reductive activation of the alkali metal salts, sublimation, trapping, and escape of the active species on the support in the catalytic combustion. The unique roles of LSCMP are deduced.

通过将碳酸盐负载在碳、氧化铝和钙钛矿型氧化物 (La_<0.8> Sr_<0.2> Cr_<0.5> Mn_< 0.45> Pt_<0.05> O_3, LSCMP)的催化活性。还对作为典型过渡金属氧化物催化剂的V_2O_5/γ-Al_2O_3进行了测量以进行比较，碳负载碳酸钾在723 K时表现出催化剂中最大的初始燃烧速率，而3小时内实现的转化率几乎与燃烧成正比。 V_2O_5γ-Al_2O_3的碱金属与碳的比例也显示出随着催化剂用量的增加，转化率呈线性增加，尽管斜率小得多，这表明相比之下，LSCMP 负载的碳酸盐在碱金属与碳的比率低至 0.012 时表现出高转化率，表明催化转换数非常大，而初始活性与碳上的相同盐相当。然而，负载在 γ-Al_2O_3 和 LSCMP 上的碳酸盐在 673 K 下表现出非常有限的活性，负载在 LSCMP 上的碳酸盐比负载在碳上的碳酸盐表现出更高的活性。碱金属碳酸盐似乎在较低温度下对 LSCMP 具有活性，还测量了其他碱金属碳酸盐的活性，以检查 LSCMP 载体的作用，并从碱金属盐的还原活化、升华、捕获的角度讨论了结果。，以及催化燃烧中活性物质在载体上的逸出 LSCMP 的独特作用被推论出来。