Effect of the Preparation Method on Cu-MOR/g-C3N4 for Direct Methanol Synthesis from Methane Oxidation by Photothermal Catalysis

Abstract

Copper-based zeolite catalysts are widely used in methanol synthesis from methane oxidation, but their photothermal catalytic properties have seldom been explored. This study examines the effect of the preparation method on Cu-based zeolite composite graphite-phase carbon nitride catalysts (Cu-MOR/g-C3N4) for direct methanol synthesis from methane oxidation by photothermal catalysis. Four different preparation methods are employed: liquid phase ion exchange (Cu-MOR/g-C3N4-IE), isovolumetric impregnation (Cu-MOR/g-C3N4-IM), solid-state ion exchange (Cu-MOR/g-C3N4-GR), and hydrothermal synthesis (Cu-MOR/g-C3N4-HT). Cu-MOR/g-C3N4-IE shows the highest methanol yield (3.09 μmol h−1 gcat−1) due to strong interactions between the CuxOy species and g-C3N4, as well as smaller interfacial charge transfer forces. This study provides a new method for the design and synthesis of catalysts for the conversion of methane.