Optimizing Gd-Ni/MCM-41 catalyst for H2-rich syngas production via CH4 partial oxidation

Background

Methane is a highly potent greenhouse gas and one of the major culprits of global warming. Partial oxidation of methane (POM) is a catalytic route for getting hydrogen-rich syngas upon mitigation of methane. However, achieving > 80 % H₂ yield at low temperatures as 600 °C remains challenging.

Methods

Herein, 5 wt. % Ni supported over MCM-41 (an ordered mesoporous silicate) and 0.5–2 wt. % Gd promoted 5Ni/MCM-41 are prepared by impregnation method and investigated for POM at 600 °C. To validate activity results, catalysts are characterized by surface area and porosity, X-ray diffraction, Temperature programmed techniques, thermogravimetric analysis, Transmission electron microscopy, and X-ray photo electron microscopy.

Significant findings

Increasing loading of Gd over 5Ni/MCM-41catalysts is found to optimize the size of Ni crystallite as low as 7.6 nm (than 22.2 nm in 5Ni/MCM-41), to enhance the surface area up to 25 % and to expand the pore volume up to 28 %. At optimum Gd loading (1 wt. %), all active sites are generated, and ∼85 % H₂ yield with 2.3 H₂/CO ratio is achieved constantly up to 240 min on stream. The low reaction temperature requirement (600 °C) and achieving consistently high H₂ yield make the 5Ni1Gd/MCM-41 catalyst reasonable for the next level of catalytic development for industrial applications.