JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2021
·Vol. 99
·期 2
·420-429
·
IF 2.326
Shen Qiuwan,Jiang Yuhang,Li Shian,Yang Guogang,Zhang Hongpeng,Zhang Zhonggang,Pan Xinxiang
Achieving efficient and stable hydrogen production has always been the focus of the industry, and ethanol steam reforming (ESR) is one of the most reliable, recyclable, and cheap technologies. Perovskite nanocomposite catalysts LaNi x Co 1 − x O 3− δ ( x = 0, 0.5, 0.9) have been prepared by an EDTA-citric acid complexing sol–gel method and used for hydrogen production by ESR. A scanning electron microscopy (SEM), X‐ray diffraction (XRD), EDS and BET were used to characterize the crystal structure of the fresh and the reduced LaNi 0.5 Co 0.5 O 3− δ . The optimal operating parameters of ESR experiments by Ni-doped LaNi x Co 1 − x O 3− δ perovskites were evaluated in detail. Results indicate that the optimum conditions for ESR are as below: reforming temperature is 600 °C; the molar ratio of H 2 O/C 2 H 5 OH is 5:1. In addition, the stable performance of LaNi 0.5 Co 0.5 O 3− δ under the optimal operating condition was examined. Under the optimal reaction conditions, ethanol conversion of LaNi 0.5 Co 0.5 O 3− δ perovskite as an ESR catalyst can reach the highest 90.2%. The results show that LaNi 0.5 Co 0.5 O 3− δ has excellent stability and catalytic activity.
研究领域:
能源化学
·
催化科学
·
材料工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Kai Shi,Yang Deng,Xia An,Xu Wu,Xianmei Xie
This work focused on optimizing the synergistic effect between CeO 2 and Ni in CeO 2 modified Ni/MgAl 2 O 4 . Six catalysts for ethanol steam reforming (ESR), including NiCeMgAl, CeO 2 /NiMgAl, Ni/CeMgAl, Ni-CeO 2 /MgAl 2 O 4 , Ni/CeO 2 /MgAl 2 O 4 and CeO 2 /Ni/MgAl 2 O 4 , were synthesized by sol–gel and/or impregnation methods, which controlled the introduction order of Ce(NO 3 ) 3 . Ni/CeMgAl showed a satisfactory stability with 90.6 % of ethanol conversion after 100 h test, 66.9 % of H 2 concentration in product, and an excellent anti-coking ability with 0.72 mg c /(g cat ·h). The optimal catalytic performance of Ni/CeMgAl benefits from the unique distribution of components, which provides adequate Ni 0 active sites for C-C bonds scission, maintains a stable particle size of metallic Ni, and suppresses the side reactions and carbonization of intermediates on CeO 2 sites. This work illuminates the important of coordinating the ability of Ni and CeO 2 for ESR and presents a new insight into the design of low-cost and high-performance catalysts in practical applications.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Kai Shi,Yin Che,Yang Deng,Xia An,Xianmei Xie,Xu Wu
Bimetallic catalysts with unique geometric and electronic structure exhibit high performance compared to that of monometallic counterparts in the ethanol steam reforming (ESR). Herein, NiCo bimetals supported on CeO 2 doped MgAl 2 O 4 (NiCo/CeMgAl) with different ratio of Ni/Co were prepared for ESR. The synergies between Ni and Co in catalytic activities and ability to anti-coking were focused. The results demonstrate Co atoms trend to segregate toward the surface and are oxidized synchronously, forming the Ni-CoO hybrid surface. The reduced Ni particles are beneficial to maintain a stable catalytic activity for the C-C bonds scission, and the CoO particles formed by segregation and irreversible oxidation of Co 0 are more conducive to activation of H 2 O, the resulting OH promotes the transformation of CH x species, which significantly reduces the selectivity of CH 4 and prevents the formation of filamentous carbon. Controlling Co content and maintaining a stable M/M δ+ are critical to balance the C-C bond scission reaction and the CH 3 * conversion reaction on the NiCo bimetallic catalysts. The optimal catalyst 9Ni1Co/CeMgAl shows the ethanol conversion of 93.9 % at TOS of 100 h, and the average rate of coke formation is 0.50 mg c ·g cat -1 ·h −1 .
研究领域:
化学工程
·
催化
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Mengting Wang,Jiajun Yang,Bo Chi,Jian Pu,Jian Li
La 0.8 Ce 0.2 Mn 0.6 Ni 0.4 O 3 with (LCMN@CuO) and without (LCMN) CuO addition are prepared by solution methods, followed by reduction in 5% H 2 –N 2 stream at 650 °C to form Ni exsolved and CuO reduced catalysts, LCMN@Ni and LCMN@Ni/Cu, for ethanol (EtOH) steam reforming (ESR). The catalysts are characterized by X-ray diffraction (XRD), scanning and transmission electron microscopies (SEM and TEM), temperature programmed reduction (H 2 -TPR), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy etc., and are evaluated for ESR with a steam/carbon ratio of 3 and a weight hourly space velocity (WHSV) of 4 h −1 at temperatures between 500 and 700 °C. Ni exsolution and CuO reduction are confirmed on the substrates in LCMN@Ni and LCMN@Ni/Cu. Both the catalysts demonstrate a complete conversion of EtOH, forming mainly H 2 , CO 2 , CO and CH 4 . And increasing temperature to 700 °C increases the yields of H 2 and CO to the levels about 90% and 40%, respectively, at the cost of CH 4 ; and such performance remains unchanged for 30 h. These results indicate that both LCMN@Ni and LCMN@Ni/Cu are promising catalysts for ESR, the main difference between them is that the latter is more chemically stable and more resistant to carbon deposition under ESR conditions.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2022
·
IF 4.632
Tingting Bao,Hui zhou,Yi Zhang,Chenxu Guo,Wenming Guo,Hang Qin,Pengzhao Gao,Hanning Xiao,Weixiong Liu
Ni/CeO 2 catalysts ( n CeO2 : n Ni = 0, 1, 4, 7, 10) supported on SiC porous ceramics for ethanol steam reforming (ESR) were investigated with respect to hydrogen production performance and growth of carbon deposition. The oxygen released from CeO 2 enables the oxidation of CH x species to serve as carbon precursors, thus providing Ni/CeO 2 catalysts with stronger resistance to carbon deposition compared with Ni catalysts. The Ni/CeO 2 catalysts prepared by inverse microemulsion and impregnation methods exhibit regular semicircular spherical shape on SiC porous ceramics. Under 500 °C for 25 h of ESR reaction, the ethanol conversion rate over Ni/CeO 2 catalysts ( n CeO2 : n Ni = 7) is sustained up to 100% and H 2 selectivity is essentially kept at 74%. The by-product selectivity declines stepwise with increasing content of CeO 2 , which is attributed to the adsorption and oxidation of CO and of CH x species as CH 4 precursor from CeO 2 . The scanning electron microscopy (SEM) and transform electron microscopy (TEM) results reveal that further loading of CeO 2 on the surface of Ni catalysts can alleviate both migration and sintering of Ni particles. Furthermore, carbon deposition on Ni/CeO 2 catalysts preferentially outgrow filamentous rather than amorphous carbon , with a tendency for the latter to be more deactivated.
研究领域:
催化化学
·
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Mingzheng Liao,Chunrun Qin,Liujie Xu,Sihan Guo,Chao Wang,Yi Li,Wei Liu,Qingbin Song,Ying Chen,Yanping Du
Ethanol has been recognized as a preferred hydrogen carrier, while coke deposition is a crucial issue during the typical ethanol steam reforming (ESR) process for hydrogen production, which hinders the catalytic stability. Polymetallic catalyst is a type of promising candidate catalyst owing to its adjustable catalytic performance, whereas its catalytic mechanism has rarely been investigated in detail. In this work, a nanorod-type quinary metal oxide NiCoMnCeCaO x was tactfully designed and synthesized. In the synthesized catalyst, transition metals (Ni, Co) were employed as active components for C-C and C-H bond cracking; oxygen carrier species (Mn, Ce) were exploited to improve the oxygen release capacity and lattice oxygen mobility; and alkali metals (Ca) were designed to enhance H 2 O absorption and CO 2 capture. It was interesting that surface reconstruction was discovered for NiCoMnCeCaO x during the initial stage of ESR, NiCo nanoalloy was self-assembly generated to form a supported-like NiCo/NiCoMnCeCaO x structure, accompanied with the gradually increased H 2 production efficiency and stable at 120.5 μmol/s with 99.92 % ethanol conversion after 20th min. The synergistic effect of the polymetallic component and the specific morphological structure of NiCoMnCeCaO x contributed to its outstanding carbon tolerance performance. It achieved efficient H 2 production through ethanol dehydration and subsequent deep dehydrogenation. The new composite material (MWCNT@NiCoMnCeCaO x ) induced by ESR reaction exhibited specific electrochemical performance. This work attempted to offer certain references for the design of multifunctional catalysts for H 2 production.
研究领域:
催化化学
·
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
FUEL
·
2020
·
IF 5.578
Rong Dai,Ziliang Zheng,Kai Shi,Xu Wu,Xia An,Xianmei Xie
Ethanol steam reforming (ESR) has drawn great attention for sustainable H 2 production. Design active and sinter resistant nanocatalysts are critical issues for ESR reaction. Herein, a core–shell structured Pt-Cu@Ni-SiO 2 nanocomposite for ESR reaction has been synthesized via a one-pot facile encapsulation strategy, which is featured by highly active and sintering resistance for ESR reaction. Structural and morphological characterizations revealed that each Pt-Cu@Ni-SiO 2 nanocomposite contained a 3 nm Pt-Cu core and multiple Ni nanoparticles with diameters of around 3 nm anchored on the SiO 2 shell. The Pt-Cu@Ni-SiO 2 nanoreactor exhibited higher ethanol conversion (99.99%) and H 2 selectivity (70.32%) and an excellent stability with no loss of activity after 50 h of reaction at 450 °C. The advantages were originated from the ultra-small size of metal nanoparticles and the unique core–shell structure provides a great opportunity to give full play to the catalytic activity of active sites thus guaranteed excellent catalytic activity. Compared with the supported Pt-Cu@Ni-SiO 2 catalyst, the Pt-Cu@Ni-SiO 2 nanoreactor exhibit good stability and sintering resistance due to the encapsulation of the metal nanoparticles and the enhanced metal-support interaction. Thus, it is supposed that this type of catalyst opens a new strategy for the design of the ESR catalyst.
研究领域:
化学工程
·
材料科学
·
催化反应
✓ 已验证
DOI
高影响因子
Nanoscale
·
2020
·Vol. 12
·期 31
·16605-16616
·
IF 6.895
Rong Dai,Ziliang Zheng,Chenshuai Lian,Kai Shi,Xu Wu,Xia An,Xianmei Xie
To enhance the catalytic performance of catalysts for the ethanol steam reforming (ESR) reaction, a facile reverse micelle strategy was adopted to prepare a core@shell Ni–Cu@Ca–SiO2 (Ni–Cu@CS) nanoreactor composed of an ultra-small Ni–Cu alloy (∼2.8 nm) encapsulated in Ca-functionalized SiO2 nanoparticles. Benefiting from its core@shell structural features and unique components, the Ni–Cu@CS nanoreactor exhibited superior activity (69.91% H2 selectivity and 99.99% ethanol conversion) and stability compared to reference samples. The regenerated Ni–Cu@CS nanoreactor showed high stability, maintaining 98.14% ethanol conversion and only 1.98 mg gcat−1 h−1 in carbon deposition. The high catalytic performance of Ni–Cu@CS is attributed to not only its encapsulated structure, which effectively prevented the sintering of neighboring Ni–Cu alloy nanoparticles, but also to its Ca-functionalized porous SiO2 shell, suppressing the carbon deposition. Moreover, its porous thin shell facilitated the mass transfer and diffusion of reactants and products. Thus, the Ni–Cu@CS nanoreactor is expected to become a new type of high-efficiency nanoreactor for the ESR reaction.
研究领域:
催化化学
·
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
ENERGY
·
2018
·
IF 4.968
Lin Li,Dawei Tang,Yongchen Song,Bo Jiang,Qian Zhang
In this work, a ceria promoted Ni-based catalyst supported in mesoporous montmorillonite (MMT) was developed and evaluated in ethanol steam reforming . This Ni-Ce/MMT catalyst was synthesized by an ultrasound assisted cation exchange impregnation method and characterized by X-ray diffraction, N 2 adsorption–desorption, H 2 temperature-programmed reduction and transmission electron microscopy. TEM images of Ni-Ce/MMT presented that narrow Ni nanoparticles (av. 6.0 nm) were uniformly deposited within the mesoporous MMT support. This was attributed to the strong interaction between Ni and ceria and the confinement effect from the framework of MMT support. The catalytic activity and stability of Ni-Ce/MMT were studied in steam ethanol reforming and compared with Ni/MMT. The higher ethanol conversion and H 2 selectivity of Ni-Ce/MMT demonstrated the addition of ceria facilities the reaction of ethanol steam reforming. Additionally, the ethanol conversion was much more stable on Ni-Ce/MMT than on Ni/MMT during a long-term ethanol steam reforming reaction, illustrating that the catalyst deactivation was preferably suppressed with the help of ceria. In short, the Ni-Ce/MMT is a promising catalyst for ethanol steam reforming owing to the remarkable effect of ceria as well as the confinement effect of MMT support which can effectively suppress the Ni sintering and carbon deposition .
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
JACS Au
·
2021
·
IF 0
Yang Wu,Chunlei Pei,Hao Tian,Tao Liu,Xianhua Zhang,Sai Chen,Quan Xiao,Xianhui Wang,Jinlong Gong
The suppression of methane and coke formation over Ni-based catalysts for low temperature ethanol steam reforming remains challenging. This paper describes the structural evolution of Fe-modified Ni/MgAl2O4 catalysts and the influence of iron species on methane and coke suppression for low temperature ethanol steam reforming. Ni–Fe alloy catalysts are gradually oxidized by water to generate Ni-rich alloy and γ-Fe2O3 species at steam-to-carbon ratio of 4. The electron transfer from iron to nickel within Ni–Fe alloy weakens the CO adsorption and effectively alleviates the CO/CO2 methanation. The oxidation capacity of γ-Fe2O3 species promotes the transformation of ethoxy to acetate groups to avoid methane formation and the elimination of carbon deposits for anticoking. Ni10Fe10/MgAl2O4 shows a superior performance with a highest H2 yield of 4.6 mol/mol ethanol at 400 °C for 15 h. This research could potentially provide instructions for the design of Ni-based catalysts for low-temperature ethanol steam reforming.
研究领域:
催化化学
·
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
PubMed
FUEL
·
2014
·
IF 3.406
Tingting Li,Junfeng Zhang,Xianmei Xie,Xuemei Yin,Xia An
Alkaline-promoted of NiAl–montmorillonite (NiAl–Mt) catalysts were prepared by ion-exchange method, tested in ethanol steam reforming (ESR) for hydrogen production, and characterized by a combination analysis of XRD, TPR, SEM, HR–TEM, EDS and N 2 adsorption–desorption. Characterization results indicated that the textural properties of the as-prepared catalysts are strongly dependent on the alkaline treatment. More importantly, a clear improvement on stability and catalytic activity, especially for the high selectivity to hydrogen, was observed in ESR. For NiAl–Mt/NaOH catalyst, ∼74.7% selectivity of hydrogen was kept at 773 K during 10-h test, while that of NiAl–hydrotalcite (NiAl) catalyst decreased from 20.4% to 5.3% within 10 h, and the selectivity of hydrogen on NiAl–Mt was ∼55.1%, accompanying with byproducts of acetaldehyde and ethylene. The improved activity and stability were attributed to the neutralization of acid sites by alkaline treatment, which accelerated the dehydrogenation and suppressed the dehydration of ethanol.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2023
·Vol. 15
·期 19
·8619-8632
·
IF 6.7
Chao Wang,Wei Liu,Mingzheng Liao,Jiahong Weng,Jian Shen,Ying Chen,Yanping Du
Catalyst sintering caused by high temperature operating conditions during ethanol steam reforming (ESR) is a common issue for traditional catalysts with low Tammann temperature metals. In recent years, high entropy oxides have been popular in thermal catalysis due to their special thermodynamics and kinetics characteristics, which is expected to be a suitable approach for enhancing catalyst stability. This paper first reports the application of HEO in ESR and the characterization. The results exhibited a nano structure (CoCrFeNiAl)3O4 HEO with a spinel-phase and was successfully synthesized by a polyol hydrothermal precipitation-calcination method. An abundance of oxygen vacancies were formed, and were further enriched in a hydrogen atmosphere as the M–O bond opened. Interestingly, its self-reorganization featured the rendered the metals spilling out of the HEO bulk phase as active species for hydrogen production during ESR, whereas the isolated metal cation randomly dissolved into the parent metal oxide cell again after the reaction instead of agglomerating over the catalyst surface. This gave the (CoCrFeNiAl)3O4 a large number of dispersed active sites, as well as a high thermal stability. In addition, 81% of the hydrogen yield as well as 85% of H2 selectivity were achieved at 600 °C. This research might offer possibilities for the development of thermal catalytic hydrogen production under high temperature conditions such as steam reforming.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）