Research Initiation Award: Novel Supported Molybdenum and Tungsten Sulfide Catalysts

本项目涉及负载型硫化钼、钴促进的硫化钼和硫化钨催化剂，这些催化剂是通过在氢或氦中分解各自的硫代硫酸盐而制备的。通过合适的测试反应确定了这些催化剂的活性，并将其与用传统方法制备的具有相同金属含量的催化剂进行了比较。考察了不同的前处理对催化剂的总面积、氧化学吸附和活性的影响。前处理包括通过程序升温还原或还原硫化去除多余的硫。对于不同的硫含量以及在每种气氛(氢或氦)中制备的催化剂，得到了氧化学吸附与催化剂活性之间的关联。负载型硫化物催化剂在煤炭液化和石油化工中起着至关重要的作用。活性硫化物催化剂通常是通过将各自的氧化物转化为硫化物来制备的，但这通常是困难的，而且不是以规则的方式进行的。这项工作探索了用不同的技术制备的催化剂的实用性，这种技术可能会产生更均匀和更活性的催化剂。

This project deals with supported molybdenum sulfide, cobalt- promoted molybdenum sulfide, and tungsten sulfide catalysts prepared by the decomposition of the respective thiosalts in hydrogen or helium. The activities of such catalysts, as determined by suitable test reactions, are compared with those of catalysts having the same metal content but prepared by conventional methods. The effects of various pretreatments on total area, oxygen chemisorption, and activity are investigated. Pretreatments include the removal of excess sulfur by temperature-programmed reduction or by reductive sulfiding. Correlations between oxygen chemisorption and catalyst activity are obtained for various sulfur contents as well as for catalysts prepared in each of the atmospheres (hydrogen or helium) for decomposition of the thiosalts. Supported sulfide catalysts play a vital role in coal liquefaction and in the petrochemical industry. Active sulfide catalysts are conventionally prepared by converting the respective oxides to sulfides, but this is often difficult and does not proceed in a regular manner. This work explores the utility of catalysts prepared by a different technique that may yield more uniform and more active catalysts.