EAGER:GOALI: Bulk Intermetallics with well-defined active sites for selectivity control in selective hydrogenations

本研究项目研究了一类新的非均相催化剂，用于轻烃选择性加氢反应生成对石化工业有价值的高价值化学中间体。选择性是指催化剂在可能产生多种产物时偏爱一种产物而不是另一种产物的能力。因此，可以通过改变催化剂的表面组成来控制选择性。这个研究项目研究了一类无机固体，金属间化合物，它们有不同大小和组成的小金属簇的有序组装。这些金属间化合物有潜力成为重要碳氢化合物加氢反应的高选择性催化剂。计算研究和实验研究正在结合起来，以确定对所需产物具有高催化活性和高选择性的催化剂组合物。晶体学上定义明确的金属间化合物被用来了解催化活性金属原子核对催化选择性的影响。金属间化合物的合成在整个γ -黄铜相中具有不同的成分，以控制核度和簇的数量。M- zn形式的金属间化合物（M = Pd， Cu和Ag）被精心选择，因为它们包含从单体到六聚体的连续簇大小的催化金属。对混合原料（炔加烯烃和烯烃加芳烃）的部分加氢反应进行了M-Zn散装金属间化合物的研究。结果将证明簇大小对催化剂选择性的影响。结果可用于确定氢化的选择性簇大小，然后将成为合成高表面积纳米颗粒形式的目标。该研究是与工业合作伙伴（埃克森美孚）合作进行的，该合作伙伴提供基于同步加速器的x射线吸收催化剂表征工具，同时还为参与该项目的研究生提供工业相关指导。

This research project investigates a new class of heterogeneous catalysts for the selective hydrogenation reactions of light hydrocarbons to higher-value chemical intermediates of value to the petrochemical industry. Selectivity refers to the ability of a catalyst to favor one product over another when multiple products are possible. As such, it is possible to control selectivity by changing the surface composition of a catalyst. This research project investigates a class of inorganic solids, intermetallic compounds, that have ordered assemblies of small metal clusters of various size and composition. These intermetallic compounds have potential as highly selective catalysts for important hydrocarbon hydrogenation reactions. Computational studies and experiment studies are being combined to identify catalyst compositions that display both high catalytic activity and high selectivity toward the desired products. Crystallographically well-defined intermetallic compounds are being utilized to understand the impact of catalytically-active metal atom nuclearity on catalytic selectivity. Intermetallic compounds are being synthesized with varying compositions across the gamma-brass phase to control both nuclearity and the number of clusters. Intermetallics of the form M-Zn (M = Pd, Cu and Ag) have been carefully chosen since they contain contiguous cluster sizes of catalytic metal from monomers to hexamers. M-Zn bulk intermetallics are being examined for partial hydrogenation reactions of mixed feedstocks (alkyne plus alkene and alkene plus aromatic). The results will demonstrate the impact of cluster size on catalyst selectivity. The results can be used to identify selective cluster sizes for hydrogenation that will then become targets for synthesis in a high surface area nanoparticle form. The study is being conducted in collaboration with an industrial partner (ExxonMobil) who provides access to synchrotron-based X-ray absorption catalyst characterization tools, while also delivering industrially-relevant guidance to the graduate students involved in the project.