In photocatalytic transition metal oxides, the surface electronic structure and carrier kinetics are complicated by charge trapping at defects as well as by carrier self-trapping as small polarons. These processes are unique to the material interface, where surface carrier dynamics deviate from bulk behavior due to the presence of surface defect states, undercoordination, or interface bonding. This talk will highlight the ability to directly visualize these processes with surface sensitivity, chemical state resolution, and ultrafast time resolution using extreme ultraviolet (XUV) reflection-absorption spectroscopy. This method measures element-specific, core-to-valence spectra analogous to x-ray absorption, but with the added benefits of surface sensitivity and ultrafast time resolution. Using this method, we investigate surface trapping and recombination in α-Fe₂O₃ and TiO₂ as two prototypical metal oxide photocatalysts. In α-Fe₂O₃, we observe ultrafast polaron formation with a rate that is three times slower than observed in bulk. Kinetic analysis reveals that this is a result of increased lattice relaxation energy for polaron formation at a surface, and we show that these rates can be rationally tuned by surface molecular functionalization. In contrast, in photoexcited TiO₂ we observe that hot holes trap as small polarons at oxygen vacancy defects in approximately 50 fs, and hot electrons couple to polar optical phonons leading to vibrational coherence and large polaron formation in approximately 1 ps. These findings provide examples of the unique opportunities enabled by XUV spectroscopy for understanding surface electron dynamics in photocatalytic systems.