Computational Studies of Chromium/Silica Catalysts

This chapter focuses on the progress of computational research on the Phillips chromium catalyst. It includes a concise review on the theoretical studies on the active site models, initiation of ethylene polymerization and cyclotrimerization of alkynes over the Phillips catalyst, and the modification of the Phillips chromium catalyst. The general molecular description of the active site of the Phillips chromium catalyst is chromium oxide supported on a highly heterogeneous silica surface. The mechanistic study on alkyne cyclotrimerization over the Phillips catalyst could shed some lights on the formation of the first chromium–carbon bond in general. The challenges in modeling the Phillips catalyst come from two aspects: the "realistic" model that can represent the high degree of heterogeneity of the silica surface and the theoretical method that can describe the molecular system more accurately.