CuO形貌对NH_(3)选择性催化氧化中活性的影响

Effect of Morphology on Activity of CuO in NH_(3) Selective Catalytic Oxidation

采用沉淀法,通过调节海藻酸钠的使用量,成功合成纳米粒子、纳米粒子/纳米棒的混合、纳米片3种形貌的CuO,测试不同形貌CuO在NH_(3)选择性催化氧化中的活性。研究发现,CuO纳米片在3者中的活性最高,反应温度在225℃时NH_(3)转化率可以达到100%,纳米片有利于CuO表面形成更多的吸附氧物种和酸性位;CuO纳米片上的吸附氧物种质量分数为45.4%,酸位数目为253μmol/g,显著高于另外2种形貌的CuO;较多的吸附氧物种和酸性位数目使CuO纳米片在NH_(3)选择性催化氧化中显示出更高的活性。

CuO with three kind of morphology was prepared by precipitation method with different amount of CgHgNaO?.The morphology was nanoparticle,mixture of nanoparticle and nanorod,nanosheet.The activity of CuO with different morphology in NH_(3) selective catalytic oxidation was measured.The activity of CuO nanosheet was the highest in three samples.NH_(3) conversion reached 100%at 225 Nanosheet would promote the formation of adsorbed oxygen species and acid sites on the surface of CuO.The content of adsorbed oxygen species on CuO nanosheet was 45.4%and the amount of acid sites was 253μmol/g,significantly higher than those on other CuO.Higher amount of adsorbed oxygen species and acid sites should be the main reason for the higher activity of CuO nanosheet in NH_(3) selective catalytic oxidation.