INFRARED STUDIES OF ADSORBED DINITROGEN ON SUPPORTED RUTHENIUM CATALYSTS FOR AMMONIA-SYNTHESIS - EFFECTS OF THE ALUMINA AND MAGNESIA SUPPORTS AND THE CESIUM COMPOUND PROMOTER
INFRARED STUDIES OF ADSORBED DINITROGEN ON SUPPORTED RUTHENIUM CATALYSTS FOR AMMONIA-SYNTHESIS - EFFECTS OF THE ALUMINA AND MAGNESIA SUPPORTS AND THE CESIUM COMPOUND PROMOTER
复制标题
DOI：
10.1021/j100095a010
复制
发表时间：
1994-11-03
影响因子：
--
通讯作者：
AIKA, K
中科院分区：
文献类型：
--
作者：
KUBOTA, J;AIKA, K
在160-300 K、N2气氛下，在2214和2168 cm（-1）处观察到Ru/Al_2O_3和Ru/MgO的红外吸收。不同的波数取决于样品的还原温度。在硝酸铯掺杂时，能带向较低的频率移动，例如Ru-Cs+/Al 2 O3的2095 cm（-1）和Ru-Cs+/MgO的1910 cm（-1）。这些频率与Ru粒子的电子态有关，而Ru粒子的电子态受载体和促进剂的影响。这些表面性质的讨论与氨合成活动。双氮在10wt%Ru/MgO上的吸附热估计为14 kJmol（-1）。通过吸附态二氮的红外吸收，研究了氧化还原循环对钌表面状态的影响。Ru颗粒变得更加分散在MgO表面的氧化还原循环。采用FTIR技术通过吸附态氮对氨催化剂进行了表征。
Infrared absorption due to adsorbed dinitrogen on Ru metals supported on Al2O3 and MgO is observed at 2214 and 2168 cm(-1), respectively, under N-2 atmosphere at 160-300 K. The different wavenumbers were obtained depending on the reduction temperature of the samples. On cesium nitrate doping, the bands shifted to lower frequencies such as 2095 cm(-1) for Ru-Cs+/Al2O3 and 1910 cm(-1) for Ru-Cs+/MgO. These frequencies are related to the electronic states of Ru particles, which are affected by the supports and the promoters. These surface natures are discussed in connection with the ammonia synthesis activities. The heat of adsorption of dinitrogen on 10 wt % Ru/MgO is estimated to be 14 kJ mol(-1). Through the infrared absorption of adsorbed dinitrogen, the change of the surface Ru state by the oxidation-reduction cycles was studied. Ru particles became more dispersed on MgO surfaces by the oxidation-reduction cycles. Active ammonia catalysts were characterized by an FTIR through the adsorbed dinitrogen.