Activation of Tungsten Oxide for Propane Dehydrogenation and Its High Catalytic Activity and Selectivity
Dehydrogenation of propane to propene is one of the important reactions for the production of higher-value chemical intermediates. In the commercial processes, platinum- or chromium oxide-based catalysts have been used for catalytic propane dehydrogenation. Herein, we first report that bulk tungsten oxide can serve as the catalyst for propane dehydrogenation. Tungsten oxide is activated by hydrogen pretreatment and/or co-feeding of hydrogen. Its catalytic activity strongly depends on hydrogen pretreatment time and partial pressure of hydrogen in the feed gas. The activation of tungsten oxide by hydrogen is attributed to reduction of the metal oxide and presence of multivalent oxidation states. Comparison of the catalytic performance of partially reduced WO3−x to other highly active metal oxides shows that WO3−x exhibits superior catalytic activity and selectivity than Cr2O3 and Ga2O3. The findings of this work provide the possibility for activation of metal oxides for catalytic reactions and the opportunity for the development of new type of catalytic systems utilizing partially reduced metal oxides.
KeywordsHeterogeneous catalysis Dehydrogenation Tungsten oxide Reduction Oxidation state
We thank the financial support from the Dow Chemical Company through funding for the Core–Shell Catalysis Project, Contract No. 20120984 to University of California, Berkeley. The user project at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. We are grateful to Dr. David Barton, Dr. Pete Nickias, and Dr. Trevor Ewers from Dow Chemical Co. for fruitful discussions. Joyce R. Araujo and B.S. Archanjo acknowledge CNPq for their fellowships 234217/2014-6 and 234217/2014-6, respectively.