Nanotubular titanate supported palladium catalysts: The influence of structure and morphology on phenol hydrogenation activity

2007 ◽  
Vol 324 ◽  
pp. 52-61 ◽  
Author(s):  
Lucky M. Sikhwivhilu ◽  
Neil J. Coville ◽  
Dhachapally Naresh ◽  
Komandur V.R. Chary ◽  
Venkataraman Vishwanathan
1997 ◽  
Vol 15 (3) ◽  
pp. 165-172 ◽  
Author(s):  
Nagendranath Mahata ◽  
V. Vishwanathan

A series of catalysts containing 1 wt.% Pd supported on various oxides of commercial origin have been characterised by hydrogen adsorption at 298 K and evaluated for vapour-phase phenol hydrogenation at 473 K employing an H/phenol ratio of 5.4 at atmospheric pressure. The activity of phenol hydrogenation showed a dependence on the irreversible uptake of hydrogen. Among the catalysts studied, Pd/Al2O3 showed a decrease in activity with increasing temperature while Pd/MgO passed through a maximum at 503 K. The Pd/MgO catalysts exhibited a higher dispersion of smaller Pd crystallites leading to higher activity and total selectivity for cyclohexanone. The higher resistance towards deactivation and better stability of the Pd/MgO catalysts suggest that the acidic sites of alumina may be responsible for deactivation, thereby accounting for the lowering of activity with Pd/Al2O3 catalysts.


Author(s):  
Lihui Fan ◽  
Luyang Zhang ◽  
Yanming Shen ◽  
Dongbin Liu ◽  
Nasarul Wahab ◽  
...  

<p>The ZSM-5, g-Al<sub>2</sub>O<sub>3</sub>, SiO<sub>2</sub> and MgO supported Pd-catalysts were prepared for the phenol hydrogenation to cyclohexanone in liquid-phase. The natures of these catalysts were characterized by XRD, N<sub>2</sub> adsorption-desorption analysis, H<sub>2</sub>-TPR, CO<sub>2</sub>-TPD and NH<sub>3</sub>-TPD. The catalytic performance of the supported Pd-catalyst for phenol hydrogenation to cyclohexanone is closely related to nature of the support and the size of Pd nanoparticles. The Pd/MgO catalyst which possesses higher basicity shows higher cyclohexanone selectivity, but lower phenol conversion owing to the lower specific surface area. The Pd/SiO<sub>2</sub> catalyst prepared by precipitation gives higher cyclohexanone selectivity and phenol conversion, due to the moderate amount of Lewis acidic sites, and the smaller size and higher dispersion of Pd nanoparticles on the surface. Under the reaction temperature of 135 <sup>o</sup>C and H<sub>2</sub> pressure of 1 MPa, after reacting for 3.5 h, the phenol conversion of 71.62% and the cyclohexanone selectivity of 90.77% can be obtained over 0.5 wt% Pd/SiO<sub>2</sub> catalyst. Copyright © 2016 BCREC GROUP. All rights reserved</p><p><em>Received: 7<sup>th</sup> March 2016; Revised: 13<sup>rd</sup> May 2016; Accepted: 7<sup>th</sup> June 2016</em></p><p><strong>How to Cite:</strong> Fan, L., Zhang, L., Shen, Y., Liu, D., Wahab, N., Hasan, M.M. (2016). Liquid-phase Hydrogenation of Phenol to Cyclohexanone over Supported Palladium Catalysts. <em>Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 11 (3): 354-362 (doi: 10.9767/bcrec.11.3.575.354-362)</p><p><strong>Permalink/DOI</strong>: <a href="http://doi.org/10.9767/bcrec.11.3.575.354-362">http://doi.org/10.9767/bcrec.11.3.575.354-362</a></p>


2012 ◽  
Vol 411-412 ◽  
pp. 105-113 ◽  
Author(s):  
Silvia F. Moya ◽  
Ruth L. Martins ◽  
Antje Ota ◽  
Edward L. Kunkes ◽  
Malte Behrens ◽  
...  

RSC Advances ◽  
2016 ◽  
Vol 6 (79) ◽  
pp. 75541-75551 ◽  
Author(s):  
Feng Jiang ◽  
Jian Cai ◽  
Bing Liu ◽  
Yuebing Xu ◽  
Xiaohao Liu

Palladium particles of different sizes obtained directly and indirectly by various methods were studied to clarify the particle size effect in the selective hydrogenation of cinnamaldehyde (CAL).


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