Low Content GaO Enables the Direct Methane Conversion.

The direct conversion of methane (CH), a main greenhouse gas, to value-added chemicals has attracted increasing attention in order to alleviate the current energy crisis and environmental concern. Nevertheless, the oriented conversion of CH to target product is formidably challenging due to the inertness of CH. In this work, we demonstrate that zeolite modified by a low amount of GaO (GS-1) can serve as a highly active and stable catalyst for direct conversion to hydrogen (H) and solid carbon. The optimal GS-1 with 0.62 wt % of Ga displays a CH conversion rate of 70.6 mol/g/h with a H productivity of 134 mol/g/h at 800 °C. Analysis on NH temperature-programmed desorption (TPD) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) suggests that the introduction of GaO can poison the acidic site of zeolite and promote the dehydrogenation of CH. This work reports a highly active and stable catalyst for direct methane conversion, which may provide a feasible strategy for the sustainable utilization of CH.