CuxOy nanoparticles and Cu–OH motif decorated ZSM-5 for selective methane oxidation to methyl oxygenates

Abstract

Copper decorated zeolites are promising candidates for the partial oxidation of methane to generate methanol with elevated energy density, nevertheless, the modulation and possible synergism between multiple Cu active sites still need to be delved in depth. Here, ZSM-5 catalysts with modulated Cu motifs were proposed using copper oxysalts as precursors through a calcination process. By modifying the contents of copper oxysalts precursors, the Cu active sites varied, and a unique M shaped trend of CH3OH productivity emerged. Attributed to the synergetic effects of CuxOy nanoparticles (adsorbing CH4 and generating *OCH3 species) and Cu–OH motif (binding CH4 and forming Si···CH3), a maximum CH3OH yield of 15975.73 μmol/gcat/h (with CH3OOH yield of 2155.59 μmol/gcat/h) and methyl oxygenates selectivity up to 72.79 % could be achieved. This work paved an efficient, low cost, and succinct way for the manufacture of catalysts with tunable active sites and high performance over methane to methanol conversion.