Synergistic Enhancement of Electron and Hole Transport by Pd Single Atoms and Gradient‐Distributed Ti <sup>3+</sup> Species for High‐Performance Photocatalytic Oxidation of CH <sub>4</sub> to Oxygenates
Kai Sun, Xinya Pei, Shengyao Wang, Xusheng Wang, Panzhe Qiao, Defa Wang, Lequan Liu, Jinhua Ye, Hui Song
Abstract
Abstract 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 TiO 2 photocatalyst incorporating atomically dispersed Pd and a gradient distribution of Ti 3+ species, achieving a remarkable C 1 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 O 2 dissociation, while the gradient‐distributed Ti 3+ species promote hole migration from the bulk to the surface, enabling efficient CH 4 activation. These spatially separated charge pathways synergistically promote the formation of • CH 3 and • OOH radicals, which couple to generate CH 3 OOH and subsequently convert into methanol and formaldehyde.