Design of Highly Active Photocatalytic System for the Removal of NOx

高活性光催化脱硝系统设计

• 批准号: 02044125
• 负责人: ANPO Masakazu
• 金额: $ 0.9万
• 依托单位: University of Osaka Prefecture
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 无数据
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02044125/
• 关键词: photocatalysis; NOx decomposition; photocatalytic decomposition; ion-echanged catalyst; copper ion catalyst; ESR measurement; FT-IR measurement; surface active site

Reducing global air pollution caused by NOx and SOx is currently an urgent and serious challenge. Utilization of photocatalytic processes in gas-solid systems also promising. In the present project, we have studied and found that Cu^<2+> ions supported on silica (Cu^<2+>/SiO_2) and Y-Zeolite (Cu^<2+>/Y-Zeolite) prepared by an ion-exchange method are easily reduced to Cu^+ ions when the Cu^<2+>/SiO_2 and Cu^<2+>/Y-Zeolite samples are evacuated at temperatures higher than 573 K and the reduced Cu^+ ions on silica (Cu^+/SiO_2) and Y-Zeolite (Cu^+/Y-Zeolite) catalysts can decompose NO molecules photocatalytically and stoichiometrically into N_2 and O_2 at 275 K.UV irradiation ( 270 nm) of the Cu^+/SiO_2 and Cu^+/Y-Zeolite catalysts in the presence of NO molecules at 275 K was found to lead to the decomposition of NO into N_2 and O_2. Decomposition of NO proceeds linearly with UV irradiation time at 275 K. The major products of NO decomposition were N_2 and O_2 with a minor formation of N_2 … More O and NO_2. These minor products were found to be secondary products of N, O, and NO, and the overall reaction was found to be stoichiometrical. Thus, these results clearly indicate that UV irradiation of the CU^+/SiO_2 catalyst (or Cu^+/Y-Zeolite) in the presence of NO leads to the photocatalytic decomposition of NO into N_2 and O_2 at 275 K.The physicochemical and photochemical properties of Cu^+ ions anchored onto SiO_2 and Y-Zeolite have been investigated by means of ESR measurements of the copper (Cu^<2+>) ions and of NO species adsorbed on the copper ions and dynamic photoluminescence measurements of the excited state of the copper (Cu^+) ions (3d^94s^1 electronic state), as well as product analysis of photodecomposition of NO molecules. These results indicate that the excited state of copper ions (Cu^+ ions) plays a significant role in the photocatalytic decomposition of NO molecules and the photoreaction involves an electron transfer from the excited state of the Cu^+ ion into an anti-bonding orbital of NO molecule within the lifetime of its excited state.Thus, the present results obtained with the Cu^+/SiO_2 and Cu^+/Y-Zeolite catalysts imply the possibility of their utilization as a potentially promising type of photocatalysts for the direct decomposition of NOx into N_2 and O_2 at around normal temperature. Less

减少由NOx和SOx造成的全球空气污染是目前一项紧迫而严峻的挑战。光催化技术在气-固体系中的应用也很有前景。在本项目中，我们研究发现，在二氧化硅上负载的Cu^<2+>离子（Cu^<2+>/SiO_2）与Y型分子筛当Cu^<2+>/SiO_2和Cu^<2+>/Y-沸石样品在高于573 K的温度下抽真空时，（Cu^+/SiO_2）和Y-沸石（Cu^+/Y-Zeolite）催化剂在275 K下能将NO分子光催化分解为N_2和O_2。在275 K下，在NO分子存在下，Cu^+/SiO_2和Cu^+/Y-Zeolite催化剂经紫外光照射（270 nm）后，NO分解为N_2和O_2。在275 K下，NO的分解与紫外光照射时间呈线性关系. NO分解的主要产物为N_2和O_2，少量生成N_2 ...更多信息 O和NO_2。发现这些次要产物是N、O和NO的次级产物，并且发现总体反应是化学计量的。因此，在本发明中，这些结果清楚地表明CU^+/SiO_2催化剂的紫外辐射在275 K下，NO在SiO_2和Y沸石上的光催化分解为N_2和O_2.用ESR方法研究了Cu^+离子在SiO_2和Y沸石上的物理化学和光化学性质.离子和吸附在铜离子上的NO物种的动态光致发光测量和铜（Cu^+）离子激发态（3d^94s^1电子态）的动态光致发光测量，以及NO分子光分解的产物分析。这些结果表明，铜离子的激发态（Cu^+离子）在NO分子的光催化分解中起着重要作用，并且光反应涉及在其激发态的寿命内从Cu^+离子的激发态到NO分子的反键轨道的电子转移。Cu^+/SiO_2和Cu^+/Y-沸石催化剂的研究结果表明，它们有可能作为一类有潜力的光催化剂，在常温下直接将NOx分解为N_2和O_2。少

项目成果

T.Fujii,A.Ishii,S.Suzuki,M.Che, M.Anpo: "Photophysics on Solid Surfaces. TimeーResolved Fluorescence Spectra of Pyrene Adsorbed on Calcinated Vycor Glass" Bull.Chem.Soc.,Jpn.,. 63. 2475-2480 (1990)

T.Fujii、A.Ishii、S.Suzuki、M.Che、M.Anpo：“固体表面上的光物理学。吸附在煅烧 Vycor 玻璃上的芘的时间分辨荧光光谱”Bull.Chem.Soc.，Jpn.,。 63.2475-2480（1990）

M. Anpo: "Preparation of Supported Vanadium Oxide by Photochemical Anchoring Method and Photocatalytic Reactions on It" J. Surf. Sci. Jpn.11. 39-44 (1990)

M. Anpo：“光化学锚定法制备负载型氧化钒及其光催化反应”J. Surf。

M. Anpo: Kluwer Academic Pul. (Dordrecht). Photochemical Conversion and Storage of Solar Energy, (1991)

M. Anpo：Kluwer 学术杂志。

安保 正一: "高分散担持触媒上での光触媒反応の光誘起反応ー分子レベルの反応機構ー" 触媒、. 33. (1991)

安房庄一：“高度分散负载型催化剂上光催化反应的光诱导反应 - 分子水平的反应机理”《催化剂》，33。（1991）

M. Anpo, C. Louis, M. Che: "Absolute Reaction Rate Constants of O_2, N_2O, and C_3H_6 with the Charge Transfer Excited Triplet State of the Highly Dispersed Anchored Mo/SiO_2 Catalyst" Chem. Express. 5. 109-112 (1990)

M. Anpo、C. Louis、M. Che：“O_2、N_2O 和 C_3H_6 与高分散锚定 Mo/SiO_2 催化剂的电荷转移激发三重态的绝对反应速率常数”。