K⁺-induced formation of granular and dense copper phyllosilicate precursor converts dimethyl oxalate to ethylene glycol in absence of H₂

The reducibility of heterogeneous Cu-based precursor greatly influences the activity and stability of the final catalysts because the excessive reduction to metallic Cu significantly deactivates the catalysts. Herein, we develop a crystallization inhibition strategy to fabricate the granular and densely stacked copper phyllosilicate precursor which possesses stronger resistance to H₂ reduction. The reduction-resistant CuSiO₃ precursor contains more abundant Cu⁺ species and oxygen deficiencies, which was verified by O₂-TPD, TGA, O XPS and Cu XAES measurements, and is beneficial for methanol dehydrogenation and dimethyl oxalate (DMO) adsorption. A high yield of 85.4% of ethylene glycol (EG) was achieved from DMO hydrogenation at 240 °C, with methanol as both the solvent and hydrogen supplier. The delicately designed synthesis of specific Cu precursor with unique properties resulted in an excellent multi-functional Cu catalyst for coupled methanol dehydrogenation and DMO hydrogenation to EG.