Molybdenum Induced Framework Reorganization in ZSM‑5 Nanopillars for Stable Oxidative Methane Coupling

ZSM‑5 nanopillars (Si/Al = 36) were synthesized under hydrothermal conditions and post‑synthetically treated with Na 2 MoO 4 to introduce atomically dispersed molybdenum (Mo) species in the framework structure. Structural characterization (XRD, TEM, MAS NMR) reveals a framework reorganization upon Mo incorporation, including a space‑group transition ( Pnma → P2 1 /n ), unit‑cell expansion, and a pronounced decrease in silanol defects. The results show about 75% reduction in silanol site density, consistent with silanol healing and partial dealumination while preserving the nanopillared morphology of the Mo‐containing ZSM‐5. Pyridine and low‑temperature CO‑probe FTIR indicate a redistribution and slight strengthening of Brønsted and Lewis acid sites. The Mo‑containing ZSM‑5 nanopillars compare to parent ZSM‐5 nanopillars showed enhanced performance in the oxidative coupling of methane (OCM), achieving higher CH 4 conversion (15% vs. 11%), markedly improved C 2+ selectivity (70% vs. 21%), and increased ethylene fraction at 775°C, while maintaining stable activity and selectivity over 45 h on stream. The results demonstrate that combining morphology control with targeted Mo‑induced framework reorganization is an effective strategy to tune acidity and obtain structurally stable zeolite nanopillars for OCM application.