Glucose‐ and Cellulose‐Derived Ni/C‐SO3H Catalysts for Liquid Phase Phenol Hydrodeoxygenation |
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Authors: | Stanislav Kasakov Dr Chen Zhao Dr Eszter Baráth Zizwe A Chase Dr John L Fulton Dr Donald M Camaioni Aleksei Vjunov Dr Hui Shi Prof?Dr Johannes A Lercher |
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Institution: | 1. Department of Chemistry and Catalysis Research Center, Technische Universit?t München, Garching 85747 (Germany);2. Current address: Shanghai Key Laboratory of Green Chemistry and Chemical Process, Department of Chemistry, East China Normal University, North Zhongshan Road 3663, 200062 Shanghai (P.R. China);3. School of Chemical and Biological Engineering, Washington State University, Pullman, WA 99364 (USA);4. Institute for Integrated Catalysis, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland WA 99352 (USA) |
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Abstract: | Sulfonated carbons were explored as functionalized supports for Ni nanoparticles to hydrodeoxygenate (HDO) phenol. Both hexadecane and water were used as solvents. The dual‐functional Ni catalysts supported on sulfonated carbon (Ni/C‐SO3H) showed high rates for phenol hydrodeoxygenation in liquid hexadecane, but not in water. Glucose and cellulose were precursors to the carbon supports. Changes in the carbons resulting from sulfonation of the carbons resulted in variations of carbon sheet structures, morphologies and the surface concentrations of acid sites. While the C‐SO3H supports were active for cyclohexanol dehydration in hexadecane and water, Ni/C‐SO3H only catalysed the reduction of phenol to cyclohexanol in water. The state of 3–5 nm grafted Ni particles was analysed by in situ X‐ray absorption spectroscopy. The results show that the metallic Ni was rapidly formed in situ without detectable leaching to the aqueous phase, suggesting that just the acid functions on Ni/C‐SO3H are inhibited in the presence of water. Using in situ IR spectroscopy, it was shown that even in hexadecane, phenol HDO is limited by the dehydration step. Thus, phenol HDO catalysis was further improved by physically admixing C‐SO3H with the Ni/C‐SO3H catalyst to balance the two catalytic functions. The minimum addition of 7 wt % C‐SO3H to the most active of the Ni/C‐SO3H catalysts enabled nearly quantitative conversion of phenol and the highest selectivity (90 %) towards cyclohexane in 6 h, at temperatures as low as 473 K, suggesting that the proximity to Ni limits the acid properties of the support. |
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Keywords: | carbon support IR spectroscopy nanoparticles phenol hydrodeoxygenation X‐ray absorption spectroscopy |
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