Water–gas shift activity of K-promoted (Ni)Mo/γ-Al2O3 systems in sulfur-containing feed

Nikolova, D.; Edreva-Kardjieva, R.; Grozeva, T.

doi:10.1007/s11144-011-0300-9

Cited by 12 publications

(3 citation statements)

References 30 publications

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“…The S/Mo ratios in supported Mo–S catalysts trended in the following order: Mo–S/ZrO 2 (0.84) > Mo–S/Al 2 O 3 (0.67) > Mo–S/TiO 2 (0.43) > Mo–S/SiO 2 (0.24) > Mo–S/CeO 2 (0.16). This result agreed with the trend of MoO 3 reducibility and correlated with the CO consumption rate observed after 72 h of WGS reaction (Figure ) and strongly suggested that the Mo–S species are responsible for the WGS activity of supported Mo–S catalysts. − …”

Section: Results and Discussionsupporting

confidence: 87%

Support Effects on Water Gas Shift Activity and Sulfur Dependence of Mo Sulfide Catalysts

Yun

Guliants

2019

Energy Fuels

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Molybdenum (Mo) sulfide catalysts supported on ZrO2, Al2O3, TiO2, CeO2, and SiO2 were prepared by the incipient wetness impregnation method and explored with respect to their catalytic activity and H2S dependence in the water gas shift (WGS) reaction. The highest WGS activity at 450 °C and S/Mo atomic ratio among all Mo sulfide catalysts investigated were observed for the Mo–S/ZrO2 catalyst. Moreover, the WGS activity of the Mo–S/ZrO2 catalyst was stable for 72 h of reaction, regardless of the presence of H2S in the feed. The extent of sulfidation of supported Mo–S catalysts increased with decreasing MoO3 reduction temperature in temperature-programmed reduction, which indicated a decreased strength of MoO3–support interactions. A comparison of fresh and used supported Mo catalysts suggested that the active Mo–S sites of the Mo–S/ZrO2 catalyst maintained their catalytic activity without the crystallization of Mo–S species during 72 h of WGS reaction. Therefore, ZrO2 was indicated by this study as a promising support for the Mo-based WGS catalysts.

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Section: Results and Discussionsupporting

confidence: 87%

Support Effects on Water Gas Shift Activity and Sulfur Dependence of Mo Sulfide Catalysts

Yun

Guliants

2019

Energy Fuels

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“…18 A NiMo-based catalyst for the WGS reaction is also investigated with less publication. [19][20][21] One of the interesting recent catalyst developments in sulfur tolerant catalysts is the use of lanthanide oxysulphides (La 2 O 2 S or Pr 2 O 2 S) for high temperature WGS and RWGS reactions at high concentration of sulfur. The unique properties of this catalyst are that even though it has no transition metal which is commonly used in WGS catalysts, it has a very large oxygen storage capacity which makes it able to perform WGS at an ultra-high temperature (>600 °C) in the presence of high concentration of sulfur.…”

Section: Introductionmentioning

confidence: 99%

Sulfur resistant La_xCe_1−xNi_0.5Cu_0.5O₃ catalysts for an ultra-high temperature water gas shift reaction

Oemar

Bian

Hidajat

et al. 2016

Catal. Sci. Technol.

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A series of La x Ce 1−x Ni 0.5 Cu 0.5 O 3 catalysts was synthesized to study the effect of Ce substitution for La. XRD results show that only a small amount of Ce (10%) is allowable to substitute La to maintain the perovskite structure. The La 0.9 Ce 0.1 Ni 0.5 Cu 0.5 O 3 catalyst has the smallest metal particle size and the highest oxygen mobility among all tested catalysts as observed from the XRD, TPD-O 2 , and XPS results of reduced catalysts. These two factors are very important in achieving the highest catalytic activity of the La 0.9 Ce 0.1 Ni 0.5 Cu 0.5 O 3 catalyst in a water gas shift reaction at 450-650°C. In the presence of H 2 S, the catalytic activity at lower temperature was suppressed due to the formation of stable SO 4 2− species on the metal. However, since the amounts of surface oxygen species and adsorbed H 2 S are much lower at high temperature, the formation of SO 4 2− species is not observed, resulting in higher catalytic activity. The presence of H 2 S at high temperature enhances the formation of formate species, which can decompose to produce methane as the side product of the water gas shift reaction. IntroductionThe Water Gas Shift (WGS) reaction is one of the key reactions for hydrogen production in industry. The reaction is favorable at a low reaction temperature due to exothermicity. However, the reaction rate is lower at lower temperatures. Hence, the WGS reaction is industrially performed in two stages, i.e. high temperature WGS at 350-450°C to increase the reaction rate using an Fe-Cr catalyst, followed by low temperature WGS at 200-250°C to convert the remaining CO in the system using a Cu-Zn catalyst. With current growing interest in hydrogen production via biomass gasification technology which produces sulfur containing syngas, it is important to develop a new catalyst having high activity and stability not only at low (200-250°C) and high temperature (350-450°C) WGS reactions but also at ultra high temperatures (500-650°C) in the presence of a wide range of sulfur concentration. It is understood that biomass gasification is usually performed at high temperatures of 700-900°C. The syngas produced from the biomass gasification has a temperature of 700°C while the conventional WGS reaction requires lower reaction temperatures (200-450°C ). Hence, the syngas needs cooling for the reaction to take place, which means energy loss. The ultra high temperature WGS reaction can minimize the energy loss due to cooling of syngas. The consequences of having a sulphur resistant WGS catalyst is that the downstream hydrogen separation process should have sulphur resistant properties as well. Hence, there is growing interest in sulphur resistant H 2 separation membranes. 1 Various types of sulfur-resistant catalysts have been reported in the literature, such as W-based catalysts, 2,3 Mobased catalysts 4-7 lanthanide oxysulfide La 2 O 2 S, 8,9 noble metal catalysts (Rh,10,(11)(12)(13)), and phosphide catalysts. 14 Sulphided CoMo catalysts in promoted and unpromoted systems have been extensively...

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“…In addition, Re is a good choice to replace the Pt group metal catalyst due to its excellent electrochemical properties, lower cost compared to Pt metal and sustainable sources. Recently, water-gas shift activity in Re-based catalysts was studied, and the results showed that Re supported on an alumina catalyst promoted by K and Co exhibited an excellent performance for the WGS reaction [12]. In addition, the water-gas shift activity of Pt-Re bimetallic and Pt alone supported on a zirconia-doped ceria has been evaluated [13].…”

Section: Introductionmentioning

confidence: 99%

Effect of Re Addition on the Water–Gas Shift Activity of Ni Catalyst Supported by Mixed Oxide Materials for H2 Production

et al. 2023

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Water–gas shift (WGS) reaction was performed over 5% Ni/CeO2, 5% Ni/Ce-5% Sm-O, 5% Ni/Ce-5% Gd-O, 1% Re 4% Ni/Ce-5% Sm-O and 1% Re 4% Ni/Ce-5% Gd-O catalysts to reduce CO concentration and produce extra hydrogen. CeO2 and M-doped ceria (M = Sm and Gd) were prepared using a combustion method, and then nickel and rhenium were added onto the mixed oxide supports using an impregnation method. The influence of rhenium, samarium and gadolinium on the structural and redox properties of materials that have an effect on their water–gas shift activities was investigated. It was found that the addition of samarium and gadolinium into Ni/CeO2 enhances the surface area, reduces the crystallite size of CeO2, increases oxygen vacancy concentration and improves Ni dispersion on the CeO2 surface. Moreover, the addition of rhenium leads to an increase in the WGS activity of Ni/CeMO (M = Sm and Gd) catalysts. The results indicate that 1% Re 4% Ni/Ce-5% Sm-O presents the greatest WGS activity, with the maximum of 97% carbon monoxide conversion at 350 °C. An increase in the dispersion and surface area of metallic nickel in this catalyst results in the facilitation of the reactant CO adsorption. The result of X-ray absorption near-edge structure (XANES) analysis suggests that Sm and Re in 1% Re 4% Ni/Ce-5% Sm-O catalyst donate some electrons to CeO2, resulting in a decrease in the oxidation state of cerium. The occurrence of more Ce3+ at the CeO2 surface leads to higher oxygen vacancy, which alerts the redox process at the surface, thereby increasing the efficiency of the WGS reaction.

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Water–gas shift activity of K-promoted (Ni)Mo/γ-Al2O3 systems in sulfur-containing feed

Cited by 12 publications

References 30 publications

Support Effects on Water Gas Shift Activity and Sulfur Dependence of Mo Sulfide Catalysts

Support Effects on Water Gas Shift Activity and Sulfur Dependence of Mo Sulfide Catalysts

Sulfur resistant La_xCe_1−xNi_0.5Cu_0.5O₃ catalysts for an ultra-high temperature water gas shift reaction

Effect of Re Addition on the Water–Gas Shift Activity of Ni Catalyst Supported by Mixed Oxide Materials for H2 Production

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Water–gas shift activity of K-promoted (Ni)Mo/γ-Al2O3 systems in sulfur-containing feed

Cited by 12 publications

References 30 publications

Support Effects on Water Gas Shift Activity and Sulfur Dependence of Mo Sulfide Catalysts

Support Effects on Water Gas Shift Activity and Sulfur Dependence of Mo Sulfide Catalysts

Sulfur resistant LaxCe1−xNi0.5Cu0.5O3 catalysts for an ultra-high temperature water gas shift reaction

Effect of Re Addition on the Water–Gas Shift Activity of Ni Catalyst Supported by Mixed Oxide Materials for H2 Production

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Sulfur resistant La_xCe_1−xNi_0.5Cu_0.5O₃ catalysts for an ultra-high temperature water gas shift reaction