Crystal Phases, Defects, and Dynamics of Adsorbed Hydroxyl Groups and Water in Pure and Lanthanide-Modified Zirconia: A Neutron-Scattering Study
作者:C.K. Loong、J.W. Richardson、M. Ozawa
DOI:10.1006/jcat.1995.1329
日期:1995.12
filtered residual diffuse scattering, showed evidence of static, oxygen vacancy-induced atomic displacements along the pseudocubic 〈111〉 and other directions. The dynamics of hydrogen atoms associated with the surface hydroxyl groups and adsorbed water molecules on Ln0.1Zr0.9O1.95 and pure ZrO2 over a frequency range of 0-4400 cm−1 was investigated by neutron inelastic scattering. The stretch vibrations
通过中子光谱研究了镧系元素掺杂在氧化锆中作为稳定和促进催化反应的手段。高表面积Ln 0.1 Zr 0.9 O 1.95(Ln发现通过共沉淀法制备的La和Nd)粉末由四方对称和立方对称的混合相组成,可以在与催化应用相关的温度范围内(最高约1000°C)稳定下来。从滤波后的残余扩散散射的傅立叶变换获得的实空间相关函数显示出沿伪立方<111>和其他方向的静态,氧空位引起的原子位移的证据。在0-4400 cm -1的频率范围内,与Ln 0.1 Zr 0.9 O 1.95和纯ZrO 2上的表面羟基和吸附的水分子相关的氢原子的动力学用中子非弹性散射进行了研究。发现单斜晶ZrO 2上表面羟基的拉伸振动频率略高于Ln 0.1 Zr 0.9 O 1.95的频率。在亚单层水覆盖下,OH伸展带变宽并转移到较低的能量。在较高的覆盖率下,观察到三个带,分别对应于OH拉伸,HOH弯曲和水分子的自由运动,表明了氢键的影