Transition-Metal-Promoted Cu-SSZ-13 Catalysts for Continuous Selective Oxidation of Methane to Methanol Using Molecular Oxygen

作者：Deng, Yuandan; Lei, Huarong; Simon, Ulrich; Ye, Daiqi; Chen, Peirong^*

来源：ACS Catalysis, 2023, 14(1): 292-298.

DOI：10.1021/acscatal.3c04603

• in situ DRIFTS
• UV-vis
• Ramanspectroscopy
• Cu dimer
• Cu redox

Chabazite-type Cu-SSZ-13 zeolites can catalyze the continuous selective oxidation of methane (CH4) to methanol (CH3OH) under mild conditions using molecular oxygen (O-2) as the oxidant. Here, we demonstrate that the addition of Fe and Zn into the Cu-SSZ-13 zeolite led to an increase in space-time CH3OH yield by 138% and 68%, respectively, in the continuous CH4-to-CH3OH oxidation reaction. Comparative investigations were conducted over the pristine and Fe-loaded Cu-SSZ-13 zeolites using various ex situ and in situ methods, including X-ray absorption spectroscopy, infrared spectroscopy, ultraviolet-visible spectroscopy, Raman spectroscopy, etc., and revealed that Fe promoted the transformation of Cu2+ sites to [Cu(OH)](+), the precursor to the binuclear [Cu(trans-mu-1,2-O-2)Cu](2+) species, which is highly active for the CH4-to-CH3OH oxidation.