CeO2纳米棒负载Co催化CO脱除NOx的机理

以碱法水热合成径向尺寸6～10 nm的CeO₂纳米棒，采用湿法浸渍在纳米棒上负载不同含量的Co氧化物。通过实验探究Co含量改变对脱硝性能的影响原理，实验结果显示浸渍方案为3 g CeO₂∶30 ml 10%（质量分数） 硝酸钴溶液时，脱硝效率最高，在NO与CO摩尔比为1∶5，体积空速为30000 h^-1，无氧状态下，250℃ 即能达到70%以上的效率。采用氮气吸附、XPS、TEM以及XRD测试不同钴含量催化剂的物化性质，与催化性能结果比对分析后得出Co的添加是通过改变催化剂表面的活性官能团来提高效率，其中Co₂O₃对于催化CO与NO_x进行反应具有较高的效率，提高催化剂中Co₂O₃的比重可以将高效率温度段降低，CoO在一定程度上对CO与NO_x反应具有负面作用，而Co₃O₄对低温阶段N₂O选择性影响较大。

Mechanism of nitric oxides reduction by carbon monoxide over cobalt oxides supported by CeO2 nanorod

CeO₂ nanorod was synthesized by a hydrothermal method in alkaline solution and cobalt oxides were loaded on CeO₂ via wet impregnation methods. In order to study the effects of precursor concentration, the catalytic performances and chemical-physical characteristics of catalysts were investigated. The results indicated that the optimal precursor concentration was 10% (mass). After systematically comparing chemical-physical properties detected by nitrogen physisorption, XRD, XPS, TEM, with deNO_x performance, it can be found that Co₂O₃ was most effective component in the catalysts and increasing its fraction could greatly promote the deNO_x activity. The existence of the CoO had negative effect to the CO and NO_x reaction while Co₃O₄ caused N₂O generated at a lower temperature.