Nanoscale Metal Oxide Particles/Clusters as Chemical Reagents. Adsorption of Hydrogen Halides, Nitric Oxide, and Sulfur Trioxide on Magnesium Oxide Nanocrystals and Compared with Microcrystals
Nanoscale Metal Oxide Particles/Clusters as Chemical Reagents. Adsorption of Hydrogen Halides, Nitric Oxide, and Sulfur Trioxide on Magnesium Oxide Nanocrystals and Compared with Microcrystals
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DOI：
10.1021/cm950584h
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发表时间：
1996-08
影响因子：
8.6
通讯作者：
J. Stark;K. Klabunde
中科院分区：
文献类型：
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作者：
J. Stark;K. Klabunde
研究了纳米级 MgO（高压釜制备 = AP-MgO）和微米级 MgO（常规制备 = CP-MgO）对 HCl、HBr、NO 和 SO3 的吸附。 AP-MgO 的表面积较大，每摩尔 MgO 可以吸附这些气体的容量较高。然而，在 100 Torr 或更高的压力下，微晶上每 nm2 的 HX 和 SO3 吸附量更大。这被解释为由于在更完美的 CP-MgO 晶体上形成了有序的多层吸附物（吸附在更平坦、更延伸的平面上）。在 NO 的情况下，再次证明了 AP-MgO 与 CP-MgO 不同的表面化学性质。此时，AP-MgO吸附了更多的NO/nm2，并在表面形成了NO2、N2和N2O。纳米氧化镁的高表面积和不寻常的表面反应性使其被认为是一种新型吸附剂以及近化学计量的化学试剂。
Adsorption of HCl, HBr, NO and SO3 on nanoscale MgO (autoclave prepared = AP-MgO) and microscale MgO (conventionally prepared = CP-MgO) has been studied. The higher surface area of AP-MgO allows a higher capacity of these gases to be adsorbed/mol MgO. However, at pressures of 100 Torr or higher, the amounts adsorbed/nm2 for HX and SO3 are larger on the microcrystals. This is explained as due to the formation of ordered multilayers of adsorbate on the more perfect crystals of CP-MgO (adsorption on flatter, more extended planes). In the case of NO, the different surface chemistry of AP-MgO vs CP-MgO is again demonstrated. In this case, AP-MgO adsorbed more NO/nm2, and NO2, N2, and N2O were formed on the surface. The high surface area and unusual surface reactivity of nanoscale MgO allows it to be considered as a new type of adsorbent as well as a near-stoichiometric chemical reagent.