Organically Doped Metals—A New Approach to Metal Catalysis: Enhanced Ag-Catalyzed Oxidation of Methanol

Authors


  • This study was supported by the Israel Science Foundation (Grant # 494/05), by the US Air Force (Award # FA9550-06-1-0227), and by a joint grant from the Committee for Planning and Budgeting of the Council for Higher Education and by the Center for Absorption in Science (Israel) under the KAMEA program.

Abstract

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.

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