Effect of Nickel and Phosphorus in Hydrodesulfurization of Thiophene and Hydrodenitrogenation of Pyridine over Alumina-Supported Molybdenum Catalysts

1992 ◽  
Vol 57 (5) ◽  
pp. 1033-1042 ◽  
Author(s):  
Sonia Damyanova ◽  
Alla Spojakina ◽  
Zdeněk Vít

The effect of nickel and phosphorus on activity of alumina-supported molybdenum catalysts in simultaneous hydrodesulfurization (HDS) of thiophene and hydrodenitrogenation (HDN) of pyridine was studied. The introduction of nickel into molybdenum-containing catalysts promotes strongly HDS of the alumina-supported nickel-molybdenum catalyst while the increase in HDN activity is less pronounced. The synergistic effect in pyridine HDN is explained as the consequence of synergism in HDS. The weak promoting effect of phosphorus was observed for NiMo/Al2O3 catalyst containing 1 wt% of phosphorus. Above this concentration, both HDS and HDN activities decrease again. HDS activity of P-modified NiMo/Al2O3 samples was similar to that of the commercial NiMo/Al2O3 Shell catalyst. However, the HDN selectivity in pyridine reaction was higher for commercial catalyst which is explained by exceptionally higher dispersion of nickel on this catalyst.

Author(s):  
Junan Gao ◽  
Song Gao ◽  
Jun Wei ◽  
Hong Zhao ◽  
Jie Zhang

In this paper, the catalytic combustion of DMDS (dimethyl disulfide, CH3SSCH3) over bimetallic supported catalysts were investigated. It was confirmed that Cu/γ-Al2O3-CeO2 showed best catalytic performance among the five single-metal catalysts. Furthermore, six different metals were separately added into Cu/γ-Al2O3-CeO2 to investigate the promoting effect. The experiments revealed Pt as the most effective promoter and the the best catalytic performance was achieved as the adding amount of 0.3 wt%. The characterization results indicated that high activity and resistance to sulfur poisoning of Cu-Pt/γ-Al2O3-CeO2 could be attributed to the synergistic effect between Cu and Pt.


Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 994 ◽  
Author(s):  
Junan Gao ◽  
Song Gao ◽  
Jun Wei ◽  
Hong Zhao ◽  
Jie Zhang

In this paper, the catalytic combustion of DMDS (dimethyl disulfide, CH3SSCH3) over bimetallic supported catalysts were investigated. It was confirmed that Cu/γ-Al2O3-CeO2 showed best catalytic performance among the five single-metal catalysts. Furthermore, six different metals were separately added into Cu/γ-Al2O3-CeO2 to investigate the promoting effect. The experiments revealed Pt as the most effective promoter and the best catalytic performance was achieved as the adding amount of 0.3 wt%. The characterization results indicated that high activity and resistance to sulfur poisoning of Cu-Pt/γ-Al2O3-CeO2 could be attributed to the synergistic effect between Cu and Pt.


1990 ◽  
Vol 80 (1) ◽  
pp. 109-113 ◽  
Author(s):  
Ester P. Lorences ◽  
Gordon J. McDougall ◽  
Stephen C. Fry

The authors' methodic for assessing the role of chemical and physic-chemical factors during the structure formation of gypsum stone is presented in the article. The methodic is also makes it possible to reveal the synergistic effect and to determine the ranges of variation of controls factors that ensure maximum values of such effect. The effect of a micro-sized modifier based on zinc hydro-silicates on the structure formation of building gypsum is analyzed and corresponding dependencies are found. It is shown that effects of influence of modifier on the properties of gypsum compositions are determined by chemical properties of modifier. Among the mentioned properties are sorption characteristics (which depend on the amount of silicic acid and its state) and physicochemical properties - the ability to act as a substrate during crystal formation. The proposed method can also be extended to other binding substances and materials. This article contributes to the understanding of the processes that occur during the structure formation of composites, which will make it possible to control the structure formation in the future, obtaining materials with a given set of properties.


2005 ◽  
Vol 67 (3) ◽  
pp. 247-251 ◽  
Author(s):  
Motoi TAKENAKA ◽  
Sang Jae BAE ◽  
Shinichi SATO ◽  
Ichiro KATAYAMA

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