Journal of Materials Chemistry A
·
2022
·Vol. 10
·期 13
·7300-7313
·
IF 14.511
Zhao Sun,Junpeng Liu,Rongjun Zhang,Yu Wu,Hongwei Li,Sam Toan,Zhiqiang Sun
Sorption-enhanced steam reforming of methanol (SE-SRM) is a promising approach to creating a high-purity hydrogen supply. However, catalysts suffer from activity deactivation and low CO2 uptake capacity. In this study, we investigate the role of Ga doping of Cu–MgO in SE-SRM by synthesizing a series of MgO embedded xGaCuMg catalytic sorbents via a sol–gel method. The TEM-EDX mapping results indicate that MgO nanoparticles can be successfully embedded in the bulk-phase of the catalytic sorbent with a stabilized microstructure. The results from in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) reveal that the Ga-doped catalytic sorbent is conducive to promoting the conversion of C-containing intermediates in SE-SRM, and absorbing CO2 in the form of bidentate carbonate rather than monodentate carbonate. Experimental studies verify that the best uptake capacity of 18GaCuMg catalytic sorbent (36.25 mg CO2/g MgO) achieves almost complete conversion of methanol (99.70%) with 100% H2 selectivity at 200 °C. Specifically, no CO is formed during the kinetic-control stage of SE-SRM. Density functional theory (DFT) calculations based on the Cu(111)Ga2O3(202)MgO(200) model revealed that the Ga doping can enhance the adsorption energies of methanol and carbon dioxide, promoting methanol activation and increasing CO2 uptake capacity. These findings provide valid strategies for functionalized nanomaterial design, which will substantially promote the SE-SRMR performance with desired catalytic sorbent recyclability.
研究领域:
材料科学
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催化化学
·
能源工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Gaokui Chen,Qiuwan Shen,Xin Zhang,Tianyun Zhao,Kuanyu Zhu,Shian Li
Methanol steam reforming (MSR) is an effective way to provide high purity hydrogen for PEMFCs, however the main challenge is the toxic effect of CO. In this study, CuGa 2 O 4 spinel catalyst was applied first for MSR at low temperature. The properties of catalysts were characterized by various techniques, the MSR catalytic performance was also studied in deeply. The surface of the catalyst is composed of particle chains that are interconnected, forming high-volume pores that increase the specific surface area. The catalyst also has a rich porous structure, exposing more active sites. Furthermore, the presence of oxygen vacancies facilitates the adsorption of reactive oxygen species, reducing CO generation. A possible pathway for methanol dehydrogenation has been determined using DFT calculations. The relatively low overall energy barrier on the catalyst surface facilitates methanol activation. Among the steps, formaldehyde dehydrogenation is the rate-determining step in the methanol dehydrogenation process. The CuGa 2 O 4 catalyst exhibits good gas selectivity, with a hydrogen selectivity of 98 % and CO selectivity of 0. and no deactivation occurred within 50 h, demonstrating outstanding durability. These features allow it to serve as an efficient catalyst for MSR online hydrogen production and direct supply to PEMFCs.
研究领域:
催化化学
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能源材料科学
✓ 已验证
产品关联
DOI
高影响因子
AICHE JOURNAL
·
2019
·Vol. 66
·期 4
·e16877
·
IF 3.463
Sier Sang,Zhi-Jian Zhao,Hao Tian,Zhao Sun,Hongfang Li,Suttichai Assabumrungrat,Tahir Muhammad,Liang Zeng,Jinlong Gong
This article describes the design and synthesis of MgO-modified Ni/CaO catalysts for sorption-enhanced steam reforming of ethanol. The results show that the introduction of MgO effectively increases the dispersion of CaO via forming MgCa(CO 3 ) 2 precursor. In the prepared MgO-modified Ni/CaO catalysts, metallic Ni exists around MgO supported on CaO. Both 100% ethanol conversion and >96% hydrogen purity can be stabilized in 10 cycles over the catalyst containing 20 wt% MgO. The interaction between metallic Ni and MgO enhances the sintering resistance of the catalyst. More importantly, reaction pathway studies have confirmed that the formation of CaCO 3 hinders the activation of H 2 O on the Ni/CaO catalyst surface, and thus inhibits the conversion of the reaction intermediates including HCO* and CH x *. MgO can dissociate H 2 O to form hydroxyl groups which participate in the conversion of the reaction intermediates, thereby the MgO-modified Ni/CaO catalysts have better catalytic performance and carbon deposition resistance.
研究领域:
催化化学
·
能源材料科学
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DOI
高影响因子
Joule
·
2023
·
IF 39.8
Kai Deng,Hao Feng,Ying Zhang,Dong Liu,Qiang Li
Summary To maximize product purity, current density and efficiency has never been demonstrated simultaneously for the membrane-less water electrolyzers that eliminate the use of a membrane or a diaphragm, as well as their unfavorable issues. Here, we successfully addressed the trade-offs by leveraging the rose-petal-effect-mimetic (RPEM) design strategy. We mimicked nature by alternating water-repellent and water-adhesive building blocks; the resultant RPEM electrode is in the Cassie-impregnating wetting state, which is ideal for efficient bubble-less gas evolution reactions. A bubble-less HER at a current density of 4.2 A cm −2 , one order of magnitude larger than that of any known bubble-less electrodes, was demonstrated by the RPEM electrode. Based on this, we further constructed the RPEM electrolyzer and demonstrated membrane-less water electrolysis at 1 A cm −2 current density, simultaneously with 61.5% electrolysis efficiency and 0.003% hydrogen crossover, remarkably outperforming the state-of-the-art membrane-less water electrolyzer.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Xiao-Hui Zhang,Wei-Kun Yao,Hai-Ting Zhao,Xin-Xin Zhuang,Yan-Qi Jin,Yan Ding,Meng-Jia Li,Zhi-You Zhou,Tao Wang,Shi-Gang Sun
Low-temperature proton exchange membrane fuel cells (PEMFCs) reuqire highly pure hydrogen gas due to their extreme sensitivity to carbon monoxide (CO) contamination, which poses a challenge for using cost-effective reformed hydrogen sources. To address this issue, we have developed a surface modification strategy by applying a 0.5–0.91 nm amorphous carbon nitride layer onto PtRu/C substrates. The electrochemical measurements indicate that the modification selectively facilitates hydrogen gas transport to a surface while inhibiting carbon monoxide diffusion. The kinetic studies of CO adsorption reveal that the surface modification significantly reduces CO adsorption, effectively halving the rate compared to conventional catalysts. Additionally, rotating disk electrode experiments show that the catalyst modified with amorphous carbon nitride layer maintains stable operation for over 20 h with 1000 ppm of CO/H2. Furthermore, it supports stable discharge at 1 A cm–2 in PEMFCs with up to 10 ppm of CO, a concentration far exceeding the widely accepted standard of 0.2 ppm.
研究领域:
材料科学
·
电化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Yunlong Xia,Mengliang Gao,Ge Pu,Xingqiang Lu,Jie Gao,Jiale Wu,Qianhui Yang
The generation of high-quality syngas combined with high-purity hydrogen is an essential challenge in the chemical looping steam methane reforming (CL-SMR) process, in which the design of oxygen carriers (OCs) is crucial. In this study, La 2 FeBO 6 (B Cr, Ni，Co) and La 2 Fe 2-x Co x O 6 (x = 0.2, 0.4, 0.6, 0.8, 1.0) double perovskites have been investigated as OCs in the CL-SMR process. Various analytical techniques (BET, XPS, XRD, H 2 -TPR, Raman.) have been deployed to characterize the OCs' specific surface area, crystal structure, and surface oxygen species. The fixed-bed experiments revealed that the Cr-modified perovskite had the lowest reactivity, which was attributed to the creation of LaCrO 3 limiting the oxygen release rate of the OC. Meanwhile, Ni doping exhibited the maximum methane conversion (99.15 %), but it resulted in more carbon deposition due to methane cracking, and its carbon deposition was four times than that of Co doping. Whereas, the Co doped double perovskite OCs showed excellent overall performance, in which La 2 Fe 1.8 Co 0.2 O 6 (L 2 F 1.8 Co 0.2 ) exhibited the optimum CO selectivity (90.72 %), H 2 selectivity (96.91 %), and H 2 purity (96.84 %), as well as the lowest carbon deposition. Moreover, the L 2 F 1.8 Co 0.2 also exhibited outstanding stability in 10 cycles, and it could be a prospective material for CL-SMR, enabling the simultaneous generation of high-quality syngas and high-purity hydrogen.
研究领域:
化学工程
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材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
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