Methane production from carbon monoxide and hydrogen over nickel–alumina xerogel catalyst: Effect of nickel content

Sunhwan Hwang,송인규,Joongwon Lee,Ung Gi Hong,Jeong Gil Seo,정지철,고동준,Hyojun Lim,Changdae Byun 한국공업화학회 2011 Journal of Industrial and Engineering Chemistry Vol.17 No.1

Nickel–alumina xerogel catalysts (XNiAl) with different nickel contents (X, wt%) were prepared by a single-step sol–gel method for use in the methane production from carbon monoxide and hydrogen. The effect of nickel content on the catalytic performance of XNiAl catalysts was investigated. Conversion of CO and yield for CH4 over XNiAl catalysts drastically increased with increasing nickel content from 20 to 40 wt%, but they were almost constant at nickel content above 40 wt%. This indicates that XNiAl catalysts with nickel content above 40 wt% served as efficient catalysts in the methane production from carbon monoxide and hydrogen. The enhanced catalytic performance of nickel–alumina xerogel catalysts with nickel content above 40 wt% was attributed to the abundant active surface nickel species caused by welldeveloped framework mesopores and large pore size of the catalysts. When considering the amount of nickel used for the preparation of catalyst, it is reasonable to conclude that the optimal nickel content of nickel–alumina xerogel catalyst for methanation reaction was 40 wt%.

Methane production from carbon monoxide and hydrogen over nickel-alumina xerogel catalyst: Effect of nickel content

Hwang, S.,Lee, J.,Hong, U.G.,Seo, J.G.,Jung, J.C.,Koh, D.J.,Lim, H.,Byun, C.,Song, I.K. Korean Society of Industrial and Engineering Chemi 2011 Journal of industrial and engineering chemistry Vol.17 No.1

Nickel-alumina xerogel catalysts (XNiAl) with different nickel contents (X, wt%) were prepared by a single-step sol-gel method for use in the methane production from carbon monoxide and hydrogen. The effect of nickel content on the catalytic performance of XNiAl catalysts was investigated. Conversion of CO and yield for CH<SUB>4</SUB> over XNiAl catalysts drastically increased with increasing nickel content from 20 to 40wt%, but they were almost constant at nickel content above 40wt%. This indicates that XNiAl catalysts with nickel content above 40wt% served as efficient catalysts in the methane production from carbon monoxide and hydrogen. The enhanced catalytic performance of nickel-alumina xerogel catalysts with nickel content above 40wt% was attributed to the abundant active surface nickel species caused by well-developed framework mesopores and large pore size of the catalysts. When considering the amount of nickel used for the preparation of catalyst, it is reasonable to conclude that the optimal nickel content of nickel-alumina xerogel catalyst for methanation reaction was 40wt%.

Hydrogen production by steam reforming of liquefied natural gas (LNG) over ordered mesoporous nickel-alumina catalyst

Bang, Y.,Han, S.J.,Seo, J.G.,Youn, M.H.,Song, J.H.,Song, I.K. Pergamon Press ; Elsevier Science Ltd 2012 International journal of hydrogen energy Vol.37 No.23

An ordered mesoporous nickel-alumina catalyst (denoted as OMNA) was prepared by a single-step evaporation-induced self-assembly method, and it was applied to the hydrogen production by steam reforming of liquefied natural gas (LNG). For comparison, a nickel catalyst supported on ordered mesoporous alumina support (denoted as Ni/OMA) was also prepared by an impregnation method. Although both Ni/OMA and OMNA catalysts retained unidimensionally ordered mesoporous structure, textural properties of the catalysts were significantly affected by the preparation method. Nickel species were finely dispersed in the OMNA catalyst as a form of surface nickel aluminate with a high degree of nickel-saturation. On the other hand, both bulk nickel oxide and surface nickel aluminate phases were formed in the network of Ni/OMA catalyst. Nickel species in the OMNA catalyst exhibited not only high reducibility but also strong resistance toward sintering during the reduction process, compared to those in the Ni/OMA catalyst. Both Ni/OMA and OMNA catalysts showed a stable catalytic performance without catalyst deactivation during the steam reforming of LNG due to the confinement effect derived from well-developed ordered mesoporous structure in the catalysts. However, OMNA catalyst with small crystallite size of metallic nickel exhibited higher LNG conversion and hydrogen yield than Ni/OMA catalyst. Furthermore, OMNA catalyst was more active in the steam reforming of LNG than non-ordered mesoporous nickel-alumina catalysts prepared by common surfactant-templating methods using cationic, anionic, and non-ionic surfactants.

Hydrogen production by steam reforming of liquefied natural gas (LNG) over mesoporous nickel-alumina xerogel catalysts prepared by a single-step carbon-templating sol-gel method

Bang, Y.,Lee, J.,Han, S.J.,Seo, J.G.,Youn, M.H.,Song, J.H.,Song, I.K. Pergamon Press ; Elsevier Science Ltd 2012 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.37 No.15

A series of mesoporous nickel-alumina xerogel catalysts (denoted as CNAX) were prepared by a single-step carbon-templating sol-gel method using different amount of carbon template (X), and they were applied to the hydrogen production by steam reforming of liquefied natural gas (LNG). Textural properties of CNAX catalysts were improved with increasing the amount of carbon template. CNAX catalysts exhibited diffraction peaks corresponding to nickel aluminate phase, while CNA18 and CNA24 catalysts showed additional bulk nickel oxide phase. From TPR measurements, it was revealed that the interaction between nickel species and alumina in the CNAX catalysts became weakened with increasing the amount of carbon template. Crystallite size of metallic nickel in the reduced CNAX catalysts showed a volcano-shaped trend with respect to the amount of carbon template. In the steam reforming of LNG, CNAX (X = 0, 6, 12, and 18) catalysts exhibited a stable catalytic performance during the reaction, while CNA24 catalyst showed a significant catalyst deactivation. Crystallite size of metallic nickel served as an important factor determining the catalytic performance in the steam reforming of LNG. Initial LNG conversion and initial hydrogen yield increased with decreasing crystallite size of metallic nickel of the catalysts. Among the catalysts tested, CNA12 catalyst with the smallest crystallite size of metallic nickel showed the best catalytic performance.

Hydrogen production by steam reforming of liquefied natural gas (LNG) over trimethylbenzene-assisted ordered mesoporous nickel-alumina catalyst

Bang, Y.,Han, S.J.,Yoo, J.,Choi, J.H.,Kang, K.H.,Song, J.H.,Seo, J.G.,Jung, J.C.,Song, I.K. Pergamon Press ; Elsevier Science Ltd 2013 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.38 No.21

A trimethylbenzene (TMB)-assisted ordered mesoporous nickel-alumina catalyst (denoted as TNA) was prepared by a single-step evaporation-induced self-assembly (EISA) method, and it was applied to the hydrogen production by steam reforming of liquefied natural gas (LNG). For comparison, an ordered mesoporous nickel-alumina catalyst (denoted as NA) was also prepared by a single-step EISA method in the absence of TMB. Pore volume and average pore diameter of TNA catalyst were larger than those of NA catalyst due to structural modification caused by TMB addition in the preparation of TNA catalyst. In addition, TNA catalyst showed less ordered mesoporous array than NA catalyst. Both NA and TNA catalysts exhibited diffraction patterns corresponding to nickel aluminate phase, and they retained surface nickel aluminate phase with high stability and reducibility. Crystallite size of metallic nickel in the reduced TNA catalyst was smaller than that in the reduced NA catalyst due to strong nickel-alumina interaction of surface nickel aluminate phase over TNA catalyst. In the hydrogen production by steam reforming of LNG, TNA catalyst with small crystallite size of metallic nickel showed a better catalytic performance than NA catalyst in terms of LNG conversion and hydrogen yield. Furthermore, steam reforming reaction rather than water-gas shift reaction favorably occurred over TNA catalyst.

Effect of preparation method of mesoporous Ni-Al₂O₃ catalysts on their catalytic activity for hydrogen production by steam reforming of liquefied natural gas (LNG)

Seo, J.G.,Youn, M.H.,Jung, J.C.,Song, I.K. Pergamon Press ; Elsevier Science Ltd 2009 International journal of hydrogen energy Vol.34 No.13

Mesoporous Ni-Al<SUB>2</SUB>O<SUB>3</SUB> catalysts were prepared by impregnation method (NiAl-IP), co-precipitation method (NiAl-CP), and sequential precipitation method (NiAl-SP) for use in hydrogen production by steam reforming of liquefied natural gas (LNG). The effect of preparation method of mesoporous Ni-Al<SUB>2</SUB>O<SUB>3</SUB> catalysts on their catalytic activity for steam reforming of LNG was investigated. Physicochemical properties of Ni-Al<SUB>2</SUB>O<SUB>3</SUB> catalysts were strongly influenced by the preparation method of Ni-Al<SUB>2</SUB>O<SUB>3</SUB> catalysts. Surface area, pore volume, and average pore size of Ni-Al<SUB>2</SUB>O<SUB>3</SUB> catalysts decreased in the order of NiAl-SP>NiAl-CP>NiAl-IP. Nickel species strongly interacted with Al<SUB>2</SUB>O<SUB>3</SUB> supports through the formation of nickel aluminate phase. Surface nickel aluminate phase of Ni-Al<SUB>2</SUB>O<SUB>3</SUB> catalysts was readily reduced after the reduction process, while bulk nickel aluminate phase of NiAl-CP catalyst was hardly reducible. Nickel dispersion and nickel surface area of Ni-Al<SUB>2</SUB>O<SUB>3</SUB> catalysts decreased in the order of NiAl-SP>NiAl-CP>NiAl-IP. Among the catalysts tested, NiAl-SP catalyst with the highest nickel surface area showed the best catalytic performance in the steam reforming of LNG. Furthermore, finely dispersed nickel species in the NiAl-SP catalyst efficiently suppressed the carbon deposition during the reaction.

Hydrogen production by steam reforming of liquefied natural gas (LNG) over mesoporous nickel-phosphorus-alumina aerogel catalyst

Bang, Y.,Han, S.J.,Yoo, J.,Park, S.,Choi, J.H.,Lee, Y.J.,Song, J.H.,Song, I.K. Pergamon Press ; Elsevier Science Ltd 2014 International journal of hydrogen energy Vol.39 No.10

A mesoporous nickel-phosphorus-alumina aerogel catalyst (NPAA) was prepared by a single-step epoxide-driven sol-gel method and a subsequent supercritical CO<SUB>2</SUB> drying method for use in the hydrogen production by steam reforming of liquefied natural gas (LNG). In order to investigate the effect of drying method of nickel-phosphorus-alumina catalysts on their physicochemical properties and catalytic activities, a mesoporous nickel-phosphorus-alumina xerogel catalyst (NPAX) was also prepared by a single-step epoxide-driven sol-gel method and a subsequent evaporative drying method for comparison purpose. It was found that supercritical CO<SUB>2</SUB> drying method was effective for enhancing textural properties of NPAA catalyst. Although both NPAX and NPAA catalysts retained surface nickel aluminate phase, NPAA catalyst showed stronger metal-support interaction than NPAX catalyst. XRD patterns of reduced NPAX and NPAA catalysts revealed that NPAA catalyst retained smaller metallic nickel crystallite than NPAX catalysts. It was also observed that the reduced NPAA catalyst exhibited high nickel dispersion, large amount of strong hydrogen-binding sites, and large amount of methane adsorption compared to the reduced NPAX catalyst. In the steam reforming of LNG, NPAA catalyst with high affinity toward methane showed a better catalytic performance than NPAX catalyst.

Hydrogen production by steam reforming of liquefied natural gas (LNG) over nickel catalyst supported on mesoporous alumina prepared by a non-ionic surfactant-templating method

Seo, J.G.,Youn, M.H.,Song, I.K. Pergamon Press ; Elsevier Science Ltd 2009 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.34 No.4

A mesoporous alumina (A-NS) support was prepared by a non-ionic surfactant-templating method. A nickel catalyst supported on mesoporous alumina (Ni/A-NS) was then prepared by an impregnation method for use in hydrogen production by steam reforming of liquefied natural gas (LNG). For comparison, a nickel catalyst supported on commercial alumina (Ni/A-C) was also prepared by an impregnation method. Well-developed mesoporosity of A-NS support and strong metal-support interaction of Ni/A-NS catalyst greatly enhanced the nickel dispersion and nickel surface area through the formation of surface nickel aluminate. In the steam reforming of LNG, Ni/A-NS catalyst showed a better catalytic performance than Ni/A-C catalyst. High nickel surface area, high nickel dispersion, and well-developed mesoporosity of Ni/A-NS catalyst not only provided a large number of active nickel sites, but also suppressed the carbon deposition and nickel sintering during the reaction. Furthermore, Ni/A-NS catalyst exhibited a better catalytic performance than nickel catalyst supported on mesoporous alumina prepared by either an anionic surfactant-templating method or a cationic surfactant-templating method.

Hydrogen production by steam reforming of liquefied natural gas (LNG) over mesoporous nickel-iron-alumina catalyst

Park, S.,Bang, Y.,Han, S.J.,Yoo, J.,Song, J.H.,Song, J.C.,Lee, J.,Song, I.K. Pergamon Press ; Elsevier Science Ltd 2015 International journal of hydrogen energy Vol.40 No.17

A set of mesoporous nickel-iron-alumina xerogel catalysts (denoted as 20NixFeAl) with different iron loading (x = 0-10) were prepared by an epoxide-driven sol-gel method. The effect of iron loading on the physicochemical properties and catalytic activities of mesoporous nickel-iron-alumina xerogel catalysts in the steam reforming of liquefied natural gas (LNG) was investigated. It was found that all the calcined 20NixFeAl catalysts showed a well-developed mesoporous structure and retained finely dispersed nickel and iron species. Reducibility of calcined 20NixFeAl catalysts was enhanced by iron addition due to the increased amount of octa-coordinated nickel species. From H<SUB>2</SUB>-TPD and XPS results, it was revealed that nickel surface area of reduced 20NixFeAl catalysts showed a volcano-shaped trend with respect to iron loading. This result indicates that an optimal iron addition was required for fine dispersion of nickel species in the reduced 20NixFeAl catalysts. In the steam reforming of LNG, 20Ni4FeAl catalyst with the highest nickel surface area showed the best catalytic performance in terms of LNG conversion and hydrogen yield. Thus, nickel surface area of 20NixFeAl catalysts played a key role in determining the catalytic performance in the steam reforming of LNG.

Hydrogen production by steam reforming of natural gas over butyric acid-assisted nickel/alumina catalyst

Yoo, Jaekyeong,Park, Seungwon,Song, Ji Hwan,Yoo, Sangbeom,Song, In Kyu Pergamon Press 2017 International journal of hydrogen energy Vol.42 No.47

<P><B>Abstract</B></P> <P>A series of butyric acid (BA)-assisted nickel/alumina catalysts (denoted as XBAN/A) with different butyric acid/Ni molar ratio (X) were prepared by an impregnation method, and they were applied to the hydrogen production by steam reforming of natural gas. All the XBAN/A catalysts exhibited X-ray diffraction patterns indicative of highly stable nickel aluminate phase. However, a XBAN/A catalyst with an appropriate amount of butyric acid showed the enhanced nickel dispersion because of steric hindrance of butyric acid shell surrounding nickel particle. Addition of butyric acid also increased methane adsorption capacity of the catalysts, which was directly related to the catalytic performance. In the steam reforming of natural gas, both natural gas conversion and hydrogen yield showed volcano-shaped trends with respect to butyric acid/Ni molar ratio (X). Nickel dispersion of XBAN/A catalysts was well correlated with natural gas conversion and hydrogen yield over the catalysts. Natural gas conversion and hydrogen yield increased with increasing nickel dispersion. Among the catalysts tested, 0.25BAN/A catalyst with the highest nickel dispersion exhibited the best catalytic performance in the steam reforming of natural gas.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A series of butyric acid-assisted Ni/Al<SUB>2</SUB>O<SUB>3</SUB> (XBAN/A) catalysts were prepared. </LI> <LI> Hydrogen was produced by steam reforming of natural gas. </LI> <LI> Hydrogen yield increased with increasing methane adsorption capacity. </LI> <LI> Hydrogen yield increased with increasing nickel dispersion. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>