Nitrogen Oxide Reduction Using Methane or Methanol over Well-Characterized Dispersed Rare Earth Oxide Catalysts

CTS-9633752是甲烷还原氮氧化物研究的延伸。已经确定，某些稀土氧化物，无论是否有锶的促进，对该反应都具有高比活性，并且活性在过量氧的作用下得到增强。在这项工作中，镧和钕（散装形式的优秀催化剂），无论有没有锶促进剂，都分散在高表面积的载体上，如氧化铝、二氧化硅或氧化锆。使用多种还原剂，包括甲烷、甲醇、氢和一氧化碳，确定了在一定范围的氧分压下的催化行为和速率表达式。通过BET测量、一氧化氮和其他气体的化学吸附、x射线衍射、漫反射傅立叶变换红外光谱（DRIFTS）、电子自旋共振、热分析和同位素动力学研究对负载型稀土氧化物催化剂进行了表征。这项工作与目前控制氮氧化物排放和减少酸雨发生的努力直接相关。该技术适用于固定锅炉（电厂）源和稀燃移动（汽车）源的排放控制。

ABSTRACT CTS-9633752 This is an extension of studies on reduction of nitrogen oxides by methane. It has been established that certain rare-earth oxides, with or without promotion by strontium, have high specific activities for this reaction and activity is enhanced by excess oxygen. In this work, lanthana and neodymia (excellent catalysts in the bulk form) both with and without strontium promoter, are dispersed on high-surface-area supports such as alumina, silica, or zirconia. Catalytic behavior and rate expressions over a range of oxygen partial pressures are determined using a variety of reductants including methane, methanol, hydrogen, and carbon monoxide. The supported rare-earth-oxide catalysts are characterization by BET measurements, chemisorption of nitric oxide and other gases, X-ray diffraction, diffuse reflectance Fourier-transform infrared spectroscopy (DRIFTS), electron-spin resonance, thermal analysis, and isotopic kinetic studies. This work is directly relevant to the current efforts to control emissions of nitrogen oxides and reduce occurrence of acid rain. This technology is suitable for emission control in both stationary boiler (power plant) sources and lean-burn mobile (automotive) sources.