Synergistic Enhancement of Electron and Hole Transport by Pd Single Atoms and Gradient‐Distributed Ti 3+ Species for High‐Performance Photocatalytic Oxidation of CH 4 to Oxygenates

Photocatalytic oxidation of methane to liquid oxygenates offers a sustainable strategy for utilizing natural gas and reducing carbon emissions. However, the efficiency of current photocatalysts remains limited by poor charge carrier utilization, particularly the ineffective migration of holes that are crucial for C─H bond activation. Herein, we report a rationally engineered TiO₂ photocatalyst incorporating atomically dispersed Pd and a gradient distribution of Ti³⁺ species, achieving a remarkable C₁ oxygenates yield of 8.14 mmol·g_cat ^-1·h^-1 with 91.3% selectivity at room temperature, surpassing most state-of-the-art photocatalysts. Comprehensive characterizations and theoretical calculations reveal that Pd single atoms accelerate electron transfer and facilitate O₂ dissociation, while the gradient-distributed Ti³⁺ species promote hole migration from the bulk to the surface, enabling efficient CH₄ activation. These spatially separated charge pathways synergistically promote the formation of ^•CH₃ and ^•OOH radicals, which couple to generate CH₃OOH and subsequently convert into methanol and formaldehyde.