Another way to gain spatial control over a reaction is by attaching a molecular catalyst onto a solid support material. A rich history of surface attachment of catalysts has led to a diverse lexicon: the catalyst can be "attached", "anchored", or "immobilized" to a surface, which produces "surfacesupported" or "surface-immobilized" catalysts. Sometimes such systems are referred to as "single-site" heterogeneous catalysts because, ideally, the molecular nature of the catalyst leads to excellent homogeneity in catalyst activity, while also boasting the benefits of a heterogeneous catalyst (easy separation from reactants/products, facile recycling, etc.). An immobilized catalyst will only carry out the reaction where it is anchored to the surface, controlling the location of product generation. Furthermore, two or more catalysts can each be attached to a surface in order to prevent unwanted interactions and ensure catalyst compatibility.