The global demand for functionalized chemical products requires active and selective catalysts. Many current technologies are based on rare and expensive noble metal catalysts. Transition metal phosphides and the biomimetic transition metal chalcogenides are promising earth-abundant replacements for noble metal catalysts in many processes. These binary materials (M_nX_m) show promise for catalytic water splitting and hydrotreating, but have barely been explored in catalysis for fine-chemical synthesis. The stability, conductivity, and promising catalytic properties of M_nX_m suggest that there is a plethora of catalysis and electrocatalysis yet to be discovered. Due to their binary composition, M_nX_m surfaces will likely exhibit complementary selectivity compared to conventional metal catalysts. The goal of the proposed research program is to develop M_nX_m materials as catalysts for complex chemistry and added-value chemical products. The aim is to broadly survey catalysis of reductive and oxidative transformations with M_nX_m. The catalytic properties of M_nX_m will be tuned by chemical surface modifications. The rational development of M_nX_m as catalysts will rest on fundamental studies of structure, thermochemistry, and interfacial reactivity of the operative surfaces on a molecular-level. This will be achieved by spectroscopic surface characterization, especially in-situ surface-enhanced infrared absorption spectroscopy, stoichiometric equilibration reactions with selected reagents, and parallel study of anchored molecular analogues. The combination of catalytic survey and catalyst tuning with the underlying fundamentals will be a powerful approach to reveal novel catalysis by transition metal phosphides and chalcogenides with properties and selectivity that are currently unattainable for metal catalysts. This research could open up great opportunities for the technological application of inexpensive, earth-abundant binary materials for chemical synthesis.