Water co-catalyzed selective dehydrogenation of methanol to formaldehyde and hydrogen
| Autor: | E. Charles H. Sykes, Lawrence F. Allard, Mostafa El-Soda, Junjun Shan, Matthew D. Marcinkowski, Jilei Liu, Maria Flytzani-Stephanopoulos, Felicia R. Lucci |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Hydrogen
Chemistry Inorganic chemistry Formaldehyde chemistry.chemical_element 02 engineering and technology Surfaces and Interfaces 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Photochemistry 01 natural sciences Oxygen 0104 chemical sciences Surfaces Coatings and Films Catalysis Steam reforming Metal chemistry.chemical_compound visual_art Materials Chemistry visual_art.visual_art_medium Dehydrogenation Methanol 0210 nano-technology |
| Zdroj: | Surface Science. 650:121-129 |
| ISSN: | 0039-6028 |
| DOI: | 10.1016/j.susc.2016.02.010 |
| Popis: | The non-oxidative dehydrogenation of methanol to formaldehyde is considered a promising method to produce formaldehyde and clean hydrogen gas. Although Cu-based catalysts have an excellent catalytic activity in the oxidative dehydrogenation of methanol, metallic Cu is commonly believed to be unreactive for the dehydrogenation of methanol in the absence of oxygen adatoms or oxidized copper. Herein we show that metallic Cu can catalyze the dehydrogenation of methanol in the absence of oxygen adatoms by using water as a co-catalyst both under realistic reaction conditions using silica-supported PtCu nanoparticles in a flow reactor system at temperatures below 250 °C, and in ultra-high vacuum using model PtCu(111) catalysts. Adding small amounts of isolated Pt atoms into the Cu surface to form PtCu single atom alloys (SAAs) greatly enhances the dehydrogenation activity of Cu. Under the same reaction conditions, the yields of formaldehyde from PtCu SAA nanoparticles are more than one order of magnitude higher than on the Cu nanoparticles, indicating a significant promotional effect of individual, isolated Pt atoms. Moreover, this study also shows the unexpected role of water in the activation of methanol. Water, a catalyst for methanol dehydrogenation at low temperatures, becomes a reactant in the methanol steam reforming reactions only at higher temperatures over the same metal catalyst. |
| Databáze: | OpenAIRE |
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