Used as a coupling agent in the preparation of supported catalysts, particularly in heterogeneous catalysis. The phosphine group coordinates to metal centers, while the triethoxysilane group binds to silica or other oxide surfaces. This dual functionality allows for stable immobilization of homogeneous catalysts on solid supports, enabling easier catalyst recovery and reuse in reactions such as hydrogenation, hydroformylation, and cross-coupling. Its application is especially valuable in industrial processes where catalyst recycling and product purity are critical.