(704e) Low-Temperature Selective Oxidation of Methanol to Formaldehyde over Pt-Bi Bimetallic Catalysts

Formaldehyde is industrially manufactured by methanol selective oxidation over supported Ag or Mo-Fe catalysts in the temperature range 250-600 C. The development of alternative low temperature processes for formaldehyde production is of importance to decrease energy costs as well as capital investment resulting from the high temperature operations. In the present work, various Pt-Bi bimetallic catalysts were designed, prepared, characterized and tested for low temperature (70-120 C) methanol selective oxidation to formaldehyde. The highest selectivity toward formaldehyde (∼98%) at methanol conversion (∼8%) was achieved over the 1% Pt-0.5% Bi/AC (activated carbon) catalyst. Utilizing various characterization techniques (BET, EDX, H2-O2 titration, H2-TPR, ICP-AES, TEM, TPO, XPS and XRD) along with catalytic activity tests, the properties and catalytic performance of Pt-Bi bimetallic catalysts were correlated and discussed. The reducibility of Pt-Bi catalysts shows a linear relationship with formaldehyde selectivity, while methanol turnover frequency (TOF) values are essentially constant. Considering methanol as a simple molecule probe, the present work offers potential opportunities for selective oxidation of other alcohols at relatively low temperatures.