NH3 在多晶铜和 Cu(110) 上还原 N2O：XPS、FT-IRRAS 和动力学研究的组合,Applied Catalysis B: Environment and Energy

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NH3 在多晶铜和 Cu(110) 上还原 N2O：XPS、FT-IRRAS 和动力学研究的组合
Applied Catalysis B: Environment and Energy ( IF 20.2 ) Pub Date : 2006-01-10 , DOI: 10.1016/j.apcatb.2005.06.007
I LOUISROSE , C METHIVIER , J VEDRINE , C PRADIER

摘要在多晶Cu平面芯片(3 cm × 3 cm × 0.1 cm)或Cu(1 1 0)单晶上研究了N 2 O分解和NH 3 催化还原N 2 O的动力学。晶体，使用催化测试设备、XPS 和 FT-IRRAS 技术。已经表明，N 2 O 在金属 Cu 上分解，但随后生成 Cu 2 O，这对 N 2 O 分解有害。还原剂（例如 NH 3 ）的存在使 N 2 O 发生反应，导致其催化还原为 N 2 ；500 °C 是单独催化还原的最佳温度，即 N 2 O 或 NH 3 的附加自分解低。氧的存在量少于NH 3 的量，导致更有效的NH 3 氧化，观察到氧比NH 3 上的N 2 O更具反应性。XPS 结果能够将活性表面识别为金属Cu 和Cu 3 N，用于NH 3 氧化和NH 2 、NH、N 吸附物质作为反应的中间体。在室温下，在存在 N 2 O、O 2 和 NH 3 的情况下，FT-IRRAS 允许显示形成 NH 2 和 NH 物质（分别在 1550 和 1440 cm -1 的波段）和两个 N 2 δ - 物质（2170 和 2204 cm -1 的谱带），后者对应于吸附的 N 2 δ - 接近于吸附的电子接受 O 或 OH 物质的物质。该研究表明，在 SCR 反应过程中，N 2 O 分解为 N 2 和 O 物质；它能够识别几种吸附的表面物质（N，NH，NH 2 ，N 2 δ - ），无论是在多晶Cu芯片上在500°C催化反应后通过XPS还是通过IRRAS在Cu（1 1 0）单晶上反应物在室温下的存在。

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Reduction of N2O by NH3 on polycrystalline copper and Cu(110): A combined XPS, FT-IRRAS and kinetics investigation

Abstract Kinetics of N 2 O decomposition and catalytic reduction of N 2 O by NH 3 in the presence or absence of oxygen have been studied on polycrystalline Cu planar chip (3 cm × 3 cm × 0.1 cm) or Cu(1 1 0) single crystal, using catalytic test equipment, XPS and FT-IRRAS techniques. It has been shown that N 2 O decomposes on metallic Cu, but gives then Cu 2 O, which is detrimental to N 2 O decomposition. The presence of a reductant, such as NH 3 , allowed N 2 O to react leading to its catalytic reduction to N 2 ; 500 °C is the best temperature for catalytic reduction alone, i.e. with low additional self-decomposition of N 2 O or NH 3 . The presence of oxygen, in amount less than that of NH 3 , leads to more efficient NH 3 oxidation, oxygen being observed to be more reactive than N 2 O on NH 3 . XPS results enabled to identify the active surface as metallic Cu and Cu 3 N for NH 3 oxidation and NH 2 , NH, N adsorbed species as intermediates of the reaction. At room temperature, in the presence of N 2 O, O 2 and NH 3 , FT-IRRAS allowed to show the formation of NH 2 and NH species (bands at 1550 and 1440 cm −1 , respectively) and of two N 2 δ − species (bands at 2170 and 2204 cm −1 ), the latter one corresponding to adsorbed N 2 δ − species close to adsorbed electron accepting O or OH species. This study demonstrated that N 2 O decomposed to N 2 and O species during SCR reaction; it enabled to identify several adsorbed surface species (N, NH, NH 2 , N 2 δ − ), both by XPS after catalytic reaction at 500 °C on the polycrystalline Cu chip and by IRRAS on Cu(1 1 0) single crystal in the presence of the reactants at room temperature. In addition, it was shown that N 2 is a powerful IR probe to characterise the surrounding environment of surface sites that cannot be identified by any other way.

更新日期：2006-01-10

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