Selective hydrogenation of citral over PtSn supported on activated carbon

1994 ◽  
Vol 60 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Giovanni Neri ◽  
Andrea Donato ◽  
Candida Milone ◽  
Lucina Mercadante ◽  
A. Maria Visco
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Nicolás Carrara ◽  
Carolina Betti ◽  
Fernando Coloma-Pascual ◽  
María Cristina Almansa ◽  
Laura Gutierrez ◽  
...  

A series of low-loaded metallic-activated carbon catalysts were evaluated during the selective hydrogenation of a medium-chain alkyne under mild conditions. The catalysts and support were characterized by ICP, hydrogen chemisorption, Raman spectroscopy, temperature-programmed desorption (TPD), temperature-programmed reduction (TPR), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR micro-ATR), transmission electronic microscopy (TEM), and X-ray photoelectronic spectroscopy (XPS). When studying the effect of the metallic phase, the catalysts were active and selective to the alkene synthesis. NiCl/C was the most active and selective catalytic system. Besides, when the precursor salt was evaluated, PdN/C was more active and selective than PdCl/C. Meanwhile, alkyne is present in the reaction media, and geometrical and electronic effects favor alkene desorption and so avoid their overhydrogenation to the alkane. Under mild conditions, nickel catalysts are considerably more active and selective than the Lindlar catalyst.


2015 ◽  
Vol 275 ◽  
pp. 271-280 ◽  
Author(s):  
Yingxin Liu ◽  
Yunjiang Gu ◽  
Yaxin Hou ◽  
Yao Yang ◽  
Shuguang Deng ◽  
...  

2015 ◽  
Vol 114 (2) ◽  
pp. 629-638 ◽  
Author(s):  
Qunfeng Zhang ◽  
Lei Ma ◽  
Chunshan Lu ◽  
Xiaoliang Xu ◽  
Jinghui Lyu ◽  
...  

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Cecilia R. Lederhos ◽  
Juan M. Badano ◽  
Nicolas Carrara ◽  
Fernando Coloma-Pascual ◽  
M. Cristina Almansa ◽  
...  

Palladium, platinum, and ruthenium supported on activated carbon were used as catalysts for the selective hydrogenation of 1-heptyne, a terminal alkyne. All catalysts were characterized by temperature programmed reduction, X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. TPR and XPS suggest that the metal in all catalysts is reduced after the pretreatment with H2at 673 K. The TPR trace of the PdNRX catalyst shows that the support surface groups are greatly modified as a consequence of the use of HNO3during the catalyst preparation. During the hydrogenation of 1-heptyne, both palladium catalysts were more active and selective than the platinum and ruthenium catalysts. The activity order of the catalysts is as follows: PdClRX > PdNRX > PtClRX ≫ RuClRX. This superior performance of PdClRX was attributed in part to the total occupancy of the d electronic levels of the Pd metal that is supposed to promote the rupture of the H2bond during the hydrogenation reaction. The activity differences between PdClRX and PdNRX catalysts could be attributed to a better accessibility of the substrate to the active sites, as a consequence of steric and electronic effects of the superficial support groups. The order for the selectivity to 1-heptene is as follows: PdClRX = PdNRX > RuClRX > PtClRX, and it can be mainly attributed to thermodynamic effects.


2020 ◽  
Vol 59 (40) ◽  
pp. 17748-17761
Author(s):  
Maryam Pirmoradi ◽  
Nida Janulaitis ◽  
Robert J. Gulotty ◽  
James R. Kastner

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 2007 ◽  
Author(s):  
Stefano Cattaneo ◽  
Hadi Naslhajian ◽  
Ferenc Somodi ◽  
Claudio Evangelisti ◽  
Alberto Villa ◽  
...  

We report the use of Ru catalysts supported in the activated carbon (AC) and carbon nanofibers (CNFs) for the selective production of liquid fuel dimethylfuran (DMF) and fuel additives alkoxymethyl furfurals (AMF). Parameters such as the reaction temperature and hydrogen pressure were firstly investigated in order to optimise the synthesis of the desired products. Simply by using a different support, the selectivity of the reaction drastically changed. DMF was produced with AC as support, while a high amount of AMF was produced when CNFs were employed. Moreover, the reusability of the catalysts was tested and deactivation phenomena were identified and properly addressed. Further studies need to be performed in order to optimise the stability of the catalysts.


2018 ◽  
Vol 8 (18) ◽  
pp. 4812-4820 ◽  
Author(s):  
Rafael Castro-Amoedo ◽  
Zita Csendes ◽  
Julian Brünig ◽  
Markus Sauer ◽  
Annette Foelske-Schmitz ◽  
...  

In this work, the supported ionic liquid phase (SILP) method was applied for the immobilization of a newly developed, well-defined hydride Fe(ii) PNP pincer complex dissolved an in ionic liquid (IL) onto polymer-based spherical activated carbon.


2020 ◽  
Vol 10 (20) ◽  
pp. 7002-7015 ◽  
Author(s):  
Maryam Pirmoradi ◽  
Robert J. Gulotty ◽  
James R. Kastner

Pd–TiO2, Pd–Cu and Pd–Fe activated carbon (AC) supported catalysts were employed for continuous selective hydrogenation of furfural.


Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 177
Author(s):  
Chunshan Lu ◽  
Qianwen Zhu ◽  
Xuejie Zhang ◽  
Qiangqiang Liu ◽  
Juanjuan Nie ◽  
...  

A facile synthesis method of palladium phosphide supported on the activated carbon was developed. The effects of Pd precursors for phosphatization, phosphatization temperature, and the ratio of hypophosphite/Pd on the generation of palladium phosphide were investigated, and a generation mechanism of the Pd3P crystal structure is proposed. The results demonstrate that only PdO, rather than Pd or PdCl2, can transform into Pd phosphide without damage to the activated carbon. The penetration of P into the Pd particle can dramatically improve the dispersion of Pd species particles on the activated carbon. The generation of Pd phosphide greatly depends on the phosphatization temperature and the ratio of hypophosphite/Pd. An intact Pd3P crystal structure was obtained when the ratio of hypophosphite/Pd reached 32 and the phosphatization temperature was above 400 °C. The Pd3P supported on the activated carbon exhibited superior catalytic performance in terms of the hydrogenation of halonitrobenzenes to haloanilines because it had few L acids and B acids sites and could not generate deficient-electron active hydrogen atoms as electrophiles.


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