Preparation And Catalytic Hydrogenation Properties Of Molybdenum Disulfide Composites Pillared By Hydroxy-aluminum And Hydroxy-chromium Oligocations

Molybdenum disulfide has a layered structure with good semiconductor properties, and has been widely used as the catalysts in the hydrogenation reactions with an excellency of effectively avoiding the sulfur-toxicosis problem. Derived from the fact that there only exist the van der Waals's force between the molybdenum disulfide layers, people have developed to introduce foreign atoms or inorganic and organic molecules (or ions) as guests into its interlayer regions through synthetic methods to prepare one kind of advanced materials, layered nanocomposites. Such functional materials are in possession of diverse properties such as anisotropy, electricity, magnetism, catalysis, which are expected to make a broadly applications in the areas such as petrochemical industry, environment protection and electrode materials.This dissertation synthesized molybdenum disulfide composite materials pillared by hydroxy-aluminum, hydroxy-chromium, hydroxy-chromium/aluminum and hydroxy-iron/ aluminum oligocations through the single-molecular-layer exfoliated-restacked technology. The structures and properties of the pillared composites were investigated by means of XRD, EDS, DSC, SEM, IR, BET, GC etc. The results showed that the basal interlayer spacings for the pillared composites Al-MoS₂ are 1.488 ～ 1.599 nm, where the intercalated Keggin species are arranged in a mono-layer fashion between the molybdenum disulfide sheets with their C3 symmetry axes perpendicular to the host sheets. The basal interlayer spacings for the pillared composites Cr-MoS₂ are 1.319 ～ 1.341 nm, in where the hydroxy-chromium oligocations possibly entered the molybdenum disulfide galleries are in the form of tetranuclear polymers Cr₄⁶⁺. Introducing hydroxy-aluminum into the hydroxy-Cr₄⁶⁺ oligocations, and introducing chromium and iron ions into the hydroxy-Al₁₃⁷⁺ oligocationsions, the occurrences of substitution reactions led to the mixed hydroxy-metal oligocation formations of hydroxy-Al/Cr tetranuclear polymers, and hydroxy-Cr/Al and hydroxy-Fe/Al Keggin species, respectively. Composite materials Cr/Al-MoS₂ and Fe/Al-MoS₂ were constructed from the molybdenum disulfide layers and such hydroxy oligocations of mixed binary metals, with their basal interlayer spacings of 1.201 ～ 1.501 nm and 1.163 ～ 1.446 nm, respectively. It was indicated that when a small quantity of different metallic ions were joined unitary hydroxyl metal column, the reactions formed the substitution hydroxy oligocations without changing the...