Studies in Mineral Surface Reactivity and Geochemistry to the Atomic Level

我们提出了一个雄心勃勃的矿物表面化学项目 这将在两个平行和互补的方面进行。 其中一个项目涉及电子结构的研究 在矿物表面的单个原子位置。 另 项目涉及多相氧化还原反应。 理论，实验和分析方法将是 就业。 包括扫描隧道显微镜， 电子隧穿光谱，扫描（原子）力 显微镜、X射线和紫外光电子学 俄歇电子能谱和扫描 俄歇显微镜，低能电子衍射，和 二次电子显微镜 理论方面， 研究将主要涉及电子隧穿和 表面的电子性质。 的具体目标 在第一部分是a）计算电子结构的 “完美”和有缺陷表面上的单个原子 B）利用这些信息， 解释真空中收集的隧道图像和光谱 和非真空环境，以及c）将我们的发现 关于矿物上“反应位点”的理论/推测 表面。 第二部分的目标是：（a）确定 Mn（II）aq在矿物上氧化的具体机制 表面，B）以确定痕量的 其他对环境重要的金属，以及c）将我们的 其他非均相氧化还原和非氧化还原体系的发现 涉及含水金属与氧化物的相互作用。 如果 如果成功，我们的结果将适用于几乎所有 矿物表面化学方面。

We propose an ambitious mineral surface chemistry project that will proceed on two parallel and complementary fronts. One project deals with the study of the electronic structure of individual atomic sites on mineral surfaces. The other project deals with heterogeneous redox reactions. Theoretical, experimental, and analytic methods will be employed . Including scanning tunneling microscopy, electron tunneling spectroscopy, scanning (atomic) force microscopy, x-ray and ultraviolet photoelectron spectroscopies, Auger electron spectroscopy and scanning Auger microscopy, low energy electron diffraction, and secondary electron microscopy. Theoretical aspects of this study will deal primarily with electron tunneling and the electronic properties of surfaces. The specific objectives in Part I are a) to calculate the electronic structure of individual atoms on both "perfect" and defective surfaces of hematite, pyrite, and galena, b) to use this information to interpret tunneling images and spectra collected in vacuum and non-vacuum environments, and c) to relate our findings to theories/speculations on "reactive sites" on mineral surfaces. The objectives in Part II are a) to determine the specific mechanisms by which Mn(II)aq is oxidized on mineral surfaces, b) to determine the influence of trace amounts of other environmentally important metals, and c) to relate our findings to other heterogeneous redox and non-redox systems involving the interaction of aqueous metals on oxides. If successful, our results will be applicable to nearly every aspect of mineral surface chemistry.