CAJ | 학술논문

将高锰酸钾与活性炭(AC)原位氧化还原制备的活性炭载锰氧化物(MnOx/AC)用作臭氧分解的催化剂.采用扫描电镜、X射线光电子能谱、X射线衍射、电子自旋共振波谱、拉曼光谱以及程序升温还原研究了设计Mn负载量对负载锰氧化物性质(形貌、氧化态和晶体结构)的影响.结果表明, Mn负载量由0.44%增至11%,负载锰氧化物在活性炭表面由疏松的地衣状变为堆叠的纳米球状体,负载层的厚度由~180 nm增加至~710 nm,结构由氧化态+2.9到+3.1的低结晶β-MnOOH生长为由氧化态+3.7到+3.8的δ-MnO2结晶. MnOx/AC室温催化分解低浓度臭氧的活性与负载锰氧化物的形貌及含量密切相关. Mn负载量为1.1%的MnOx/AC具有疏松的地衣状形貌,催化分解臭氧的性能最高, Mn负载量为11%的MnOx/AC具有紧密的堆积结构,因而表现出最低的催化臭氧分解活性.
장고맹산갑여활성탄(AC)원위양화환원제비적활성탄재맹양화물(MnOx/AC)용작취양분해적최화제.채용소묘전경、X사선광전자능보、X사선연사、전자자선공진파보、랍만광보이급정서승온환원연구료설계Mn부재량대부재맹양화물성질(형모、양화태화정체결구)적영향.결과표명, Mn부재량유0.44%증지11%,부재맹양화물재활성탄표면유소송적지의상변위퇴첩적납미구상체,부재층적후도유~180 nm증가지~710 nm,결구유양화태+2.9도+3.1적저결정β-MnOOH생장위유양화태+3.7도+3.8적δ-MnO2결정. MnOx/AC실온최화분해저농도취양적활성여부재맹양화물적형모급함량밀절상관. Mn부재량위1.1%적MnOx/AC구유소송적지의상형모,최화분해취양적성능최고, Mn부재량위11%적MnOx/AC구유긴밀적퇴적결구,인이표현출최저적최화취양분해활성.
Manganese oxide catalysts supported on activated carbon (AC, MnOx/AC) for ozone decomposition were prepared by in situ reduction of the permanganate. The morphology, oxidation state, and crystal phase of the supported manganese oxide were characterized by scanning electron micros-copy, X-ray photoelectron spectroscopy, X-ray diffraction, electron spin resonance, Raman spec-troscopy, and temperature-programmed reduction. The supported MnOx layer was distributed on the surface of AC with a morphology that changed from a porous lichen-like structure to stacked nanospheres, and the thickness of the MnOx layer increased from 180 nm to 710 nm when the Mn loading was increased from 0.44% to 11%. The crystal phase changed from poorly crystallineβ-MnOOH to δ-MnO2 with the oxidation state of Mn increasing from +2.9-+3.1 to +3.7-+3.8. The activity for the decomposition of low concentration ozone at room temperature was related to the morphology and loading of the supported MnOx. The 1.1%MnOx/AC showed the best performance, which was due to its porous lichen-like structure and relatively high Mn loading, while 11%MnOx/AC with the thickest MnOx layer had the lowest activity owning to its compact morphol-ogy.