Improved Heterogeneous Catalytic Conversion of Methane to Methanol at Ambient Conditions

Abstract The heterogeneous catalytic conversion of methane to methanol with high yield under ambient temperature and pressure is reported. The new ligands L1 and L2 {L1 = 3,3′-(1,4-diazepane-1,4-diyl)bis(1-((2-(phenylamino)ethyl)(pyridin-2-ylmethyl)amino) propan-2-ol), L2 = 3,3′-(1,4-diazepane-1,4-diyl)bis(1-(phenyl(2-((pyridin-3-ylmethyl) amino) ethyl)amino) propan-2-ol)}with tricopper catalysts (C1 & C2) have been synthesized and immobilized on mesoporous silica nanoparticles (MSNs-TP) substrate. The two catalysts namely C1@MSN-TP and C2@MSN-TP improved the methane turnover by a factor of 30 compared to the reported catalysts in the literature. The aromaticity of ligand in the catalyst enhanced selective conversion of CH4 to CH3OH with the help of hydrogen peroxide (H2O2) in acetonitrile (CH3CN) solvent at ambient conditions. Improvement in the surface area of the catalysts increase the binding of L1 and L2, and then the consequent increase in uptake of CH4 in the reaction system. This improves drastically the catalytic performance of methanol turnover up to 350.