Synergetic Behavior of TiO2-Supported Pd(z)Pt(1-z) Catalysts in the Green Synthesis of Methyl Formate

Abstract

Methyl formate (MF) is a valuable platform molecule, the industrial production of which is far from being green. In this contribution, TiO2-supported Pd(z)Pt(1-z) catalysts were found to be effective in the green synthesis of methyl formate (MF) - at T=323 K and ambient pressure - through methanol (MeOH) oxidation. Two series of catalysts with similar bulk Pd/(Pd+Pt) molar ratios, z, were prepared; one by a water-in-oil microemulsion (MicE) method and the other by an incipient wetness impregnation (IWI). The MicE method led to more efficient catalysts owing to a weak influence of z on particle size distributions and nanoparticles composition. Pd(z)Pt(1-z)-MicE catalysts exhibited strong synergistic effects for MF production but weak synergistic effects for MeOH conversion. The catalytic performance of Pd(z)Pt(1-z)-MicE was superior to that of Pd(z)Pt(1-z)-IWI catalysts despite the latter displaying synergetic effects during the reaction. The catalytic behavior of TiO2-supported Pd(z)Pt(1-z) catalysts was explained from correlations between XRD, TEM, and X-ray photoelectron spectroscopy characterizations.