Orchestrating Multi-Ångstrom Spaced Cu─Ni Dual-Atom Pair for Synergistic C─H Activation in Direct Methane Oxidation to Methanol.

Direct and efficient methane oxidation to methanol is an appealing route for upgrading abundant methane resources while acquiring building blocks of clean fuels and chemicals. However, owing to its highly symmetrical nature imparted chemical stability and steric hindrance, the design of multi-ångstrom (<3.0 Å) spaced active species capable of activating its first C-H bond remains a fundamental challenge. Herein, Cu-Ni dual-atom Pair is constructed using defect engineering and a stepwise deposition method over indium oxide to precisely modulate the C-H polarization with the Cu atom showing affinity to H end and Ni anchoring the C side. The optimal CuNi/InNT achieves an oxygenates (CHOH and CHOOH) productivity of 106 mmol g h, surpassing reported systems. Theoretical calculations validate the dominating role of interatomic distance for methane activation. Specifically, the dual-atom orbital coupling effect in the minimally spaced Cu-Ni pair up-shifts the overall d-band center, significantly enhancing its hybridization with C/O 2p. Further modification through macroscopic reactor design boosts CHOH yield to 36818.84 µmol g h with 79.37% selectivity in a 1000 mL semi-industrial prototype. This work provides a comprehensive explanation of the Cu-Ni synergy, bridging atomic-scale catalysis with reactor design, and establishes a common design principle for binary catalysts at the electron and orbital level.