Tuning chemical compositions of bimetallic AuPd catalysts for selective catalytic hydrogenation of halogenated quinolines

2017 ◽  
Vol 5 (7) ◽  
pp. 3260-3266 ◽  
Author(s):  
Sai Zhang ◽  
Zhaoming Xia ◽  
Ting Ni ◽  
Huan Zhang ◽  
Chao Wu ◽  
...  
Keyword(s):  
High Activity ◽  
Catalytic Hydrogenation ◽  
Bimetallic Catalysts ◽  
Selective Adsorption ◽  
Chemical Compositions

Au1−xPdx bimetallic catalysts with low Pd entities on CeO2 nanorods delivered high activity and chemoselectivity for hydrogenation of halogenated quinolines. Improved chemoselectivity could be attributed to the selective adsorption configurations of halogenated quinolines on Au via tilted orientation rather than on Pd via flat orientation.

scholarly journals Synthesis of higher alcohols from CO 2 hydrogenation over a PtRu/Fe 2 O 3 catalyst under supercritical condition

2015 ◽  
Vol 373 (2057) ◽  
pp. 20150006 ◽  
Author(s):  
Zhenhong He ◽  
Qingli Qian ◽  
Zhaofu Zhang ◽  
Qinglei Meng ◽  
Huacong Zhou ◽  
...  
Keyword(s):  
High Activity ◽  
Bimetallic Catalysts ◽  
Supercritical Condition ◽  
Molar Ratio ◽  
Higher Alcohols ◽  
Obvious Change ◽  
Heterogeneous Hydrogenation ◽  
Hydrogenation Of Co

Hydrogenation of CO 2 to alcohols is of great importance, especially when producing higher alcohols. In this work, we synthesized heterogeneous PtRu/Fe 2 O 3 , in which the Pt and Ru bimetallic catalysts were supported on Fe 2 O 3 . The catalyst was used to catalyse CO 2 hydrogenation to alcohols. It was demonstrated that the activity and selectivity could be tuned by the bimetallic composition, and the catalyst with a Pt to Ru molar ratio of 1:2 (Pt 1 Ru 2 /Fe 2 O 3 ) had high activity and selectivity at 200°C, which is very low for heterogeneous hydrogenation of CO 2 to produce higher alcohols. The conversion and the selectivity increased with increasing pressures of CO 2 and/or H 2 . The catalyst could be reused at least five times without any obvious change in activity or selectivity.

scholarly journals The effect of platinum-aluminide coating features on high-temperature fatigue life of nickel-based superalloy Rene®80

2019 ◽  
Vol 55 (2) ◽  
pp. 235-251
Author(s):  
M.M. Barjesteh ◽  
K. Zangeneh-Madar ◽  
S.M. Abbasi ◽  
K. Shirvani
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
High Activity ◽  
Layer Thickness ◽  
Low Cycle Fatigue ◽  
Aluminide Coating ◽  
Chemical Compositions ◽  
Cycle Fatigue ◽  
Platinum Layer ◽  
Low Activity

Low cycle fatigue is the most important failure mode in Aviation/Industrial engine rotary turbine parts. In this paper, the influence of Pt-aluminide coating parameters on high temperature low cycle fatigue behavior of superalloy Rene?80 which is used to manufacture turbine blades, has been investigated. For this purpose, initial platinum layers of different thicknesses (2?m and 8?m) were coated on fatigue specimens. Then the aluminizing process was performed with two conditions of low temperature-high activity and high temperature-low activity. The results of microstructure investigations performed by scanning electron microscope and X-ray diffraction phase analysis indicated a three-layer structure for the coating (bi-phase (Ni,Pt)Al+PtAl2, single-phase (Ni,Pt)Al and interdiffusion zone) with different chemical compositions at both thicknesses of the platinum layer and using both aluminizing methods. Also, the results of low cycle fatigue tests at 871?C, R=0 and strain rate of 2?10 -3 s-1 showed a decline in fatigue properties in coated specimens as compared to uncoated sample, at total strains of 0.4, 0.8, and 1.2%. This reduction was lower in the low temperature-high activity with platinum layer thickness of 2?m, while it was more significant in the high temperature-low activity with the platinum layer thickness of 8?m. The fractography studies on coated and uncoated specimens indicated a mixed mode of ductile and brittle fracture.

Catalytic Hydrogenation of CO2 by Unsymmetric N−Heterocyclic Carbene−Nitrogen−Phosphine Ruthenium Complexes

2021 ◽  
Author(s):  
Li Ji ◽  
TIanhua Cui ◽  
Xufeng Nie ◽  
Yanling Zheng ◽  
Xueli Zheng ◽  
...  
Keyword(s):  
High Activity ◽  
Catalytic Hydrogenation ◽  
Ruthenium Complexes ◽  
Hydrogenation Of Co2 ◽  
First Time ◽  
Excellent Stability

Unsymmetric Ru-CNP and Ru-CN(H)P complexes are synthesized and applied in hydrogenation of CO2 to formate for the first time. Ru-CNP complex shows excellent stability and high activity. The TON is...

Catalytic hydrogenation of carbonyl and nitro compounds using an [N,O]-chelate half-sandwich ruthenium catalyst

2019 ◽  
Vol 48 (21) ◽  
pp. 7158-7166 ◽  
Author(s):  
Zi-Jian Yao ◽  
Jing-Wei Zhu ◽  
Nan Lin ◽  
Xin-Chao Qiao ◽  
Wei Deng
Keyword(s):  
Aqueous Solution ◽  
High Activity ◽  
Catalytic Hydrogenation ◽  
Ruthenium Complexes ◽  
Nitro Compounds ◽  
Ruthenium Catalyst ◽  
Half Sandwich

A series of N,O-chelate half-sandwich ruthenium complexes have been synthesized, which exhibited high activity for the catalytic hydrogenation of carbonyl and nitro compounds in aqueous solution.

scholarly journals High activity Pd-Fe bimetallic catalysts for aqueous phase hydrogenations

2019 ◽  
Vol 477 ◽  
pp. 110546 ◽  
Author(s):  
Yan Cheng ◽  
Hien Pham ◽  
Jiajie Huo ◽  
Robert Johnson ◽  
Abhaya K. Datye ◽  
...  
Keyword(s):  
High Activity ◽  
Aqueous Phase ◽  
Bimetallic Catalysts

scholarly journals Chiral phosphoric acid and its applications of asymmetric catalytic hydrogenation

2021 ◽  
Vol 290 ◽  
pp. 01008
Author(s):  
Sun Zhuoxin
Keyword(s):  
Phosphoric Acid ◽  
High Activity ◽  
Catalytic Hydrogenation ◽  
Catalytic Reaction ◽  
Asymmetric Catalytic ◽  
Chiral Phosphoric Acid ◽  
Asymmetric Catalytic Hydrogenation ◽  
Molecular Catalysts ◽  
Excellent Selectivity

As an excellent representative of organic small molecular catalysts, chiral phosphoric acid played an important role in asymmetric catalytic hydrogenation. According to the skeleton of chiral phosphoric acid, the development and applications of chiral phosphoric acid were summarized. The applications of chiral phosphoric acid in asymmetric catalytic hydrogenation were introduced according to three kinds of hydrogen source systems used in chiral phosphoric acid catalytic reaction. It was found that chiral phosphoric acid has high activity and excellent selectivity. Chiral products with excellent yields and enantioselectivities were obtained in most reactions.

scholarly journals Selective Hydrogenation Properties of Ni-Based Bimetallic Catalysts

Eng ◽  
2022 ◽  
Vol 3 (1) ◽  
pp. 60-77
Author(s):  
Nobutaka Yamanaka ◽  
Shogo Shimazu
Keyword(s):  
High Activity ◽  
Selective Hydrogenation ◽  
Electronic Structures ◽  
Bimetallic Catalysts ◽  
Bimetallic Nanoparticles ◽  
Ni Catalyst ◽  
Electronic Effects ◽  
Catalytic Systems ◽  
Chemoselective Hydrogenation ◽  
Hydrogenation Reactions

Metallic Ni shows high activity for a variety of hydrogenation reactions due to its intrinsically high capability for H2 activation, but it suffers from low chemoselectivity for target products when two or more reactive functional groups are present on one molecule. Modification by other metals changes the geometric and electronic structures of the monometallic Ni catalyst, providing an opportunity to design Ni-based bimetallic catalysts with improved activity, chemoselectivity, and durability. In this review, the hydrogenation properties of these catalysts are described starting from the typical methods of preparing Ni-based bimetallic nanoparticles. In most cases, the reasons for the enhanced catalysis are discussed based on the geometric and electronic effects. This review provides new insights into the development of more efficient and well-structured non-noble metal-based bimetallic catalytic systems for chemoselective hydrogenation reactions.

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