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

• Published in: ChemCatChem 2016-03, Vol.8 (6), p.1157-1166
• Main Authors: Baldovino-Medrano, Víctor G., Pollefeyt, Glenn, Bliznuk, Vitaliy, Van Driessche, Isabel, Gaigneaux, Eric M., Ruiz, Patricio, Wojcieszak, Robert
• Format: Article
• Language: English
• Subjects: Catalysis; Chemical Sciences; green chemistry; methanol oxidation; methyl formate; supported catalysts; synergy
• ISSN: 1867-3880; 1867-3899; 1867-3899
• DOI: 10.1002/cctc.201501211

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. Microemulsion or incipient wetness impregnation? TiO2‐supported Pd(z)Pt(1−z) catalysts were found to be effective in the green synthesis of methyl formate (MF) by methanol oxidation. It was determined that the water‐in‐oil microemulsion preparation method leads to highly efficient catalysts that exhibit strong synergetic effects for the production of MF. Comparison with catalysts prepared by incipient wetness (co)‐impregnation allowed the cause of such synergetic effects to be established.