Organically doped metals - A new approach to metal catalysis: Enhanced Ag-catalyzed oxidation of methanol

We report here a new approach for the modification of the performance of metal catalysts: organic doping of the metal. Specifically, we report that the doping of Ag with Congo Red (CR@Ag) significantly improves the performance of Ag as a catalyst for methanol oxidation to formaldehyde, outperforming both pure Ag and CR-coated Ag (CR/Ag) in terms of lowering the temperature needed for maximal conversion by 100°C, lowering the temperature by 200°C to reach the maximal selectivity (aldehyde formation), and increasing the maximal space velocity by a factor of two. We were led to this discovery by a detailed investigation of the thermal behavior (thermogravimetric and differential thermal analysis and mass spectroscopy) of CR@Ag under an oxidative atmosphere, which has indicated that the metal is strongly catalyzing the CR oxidation, and which pointed to the relevant temperature for activation of the catalyst.