FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Haotian Li,Feng Liu,Shuhui Wang,Fengjia Wang,Xin Qian,Caiduan Zhang,Yongliang Ma,Lidong Wang
Based on advanced oxidation technology, a new method for the simultaneous removal of SO 2 and NO x from industrial flue gas using Na 2 S 2 O 8 /MgO was proposed. The method does not require the body structure of the wet desulfurization device is changed but adds Na 2 S 2 O 8 to the original equipment to realize simultaneous desulfurization and denitrification. After determining Cl − was additive, the effects of various reaction factors on the simultaneous removal of SO 2 and NO x were investigated, including the Cl − concentration, the initial concentration of the oxidant, the initial pH value of the solution, and the reaction temperature. According to the characterization of removal products and the types of free radicals involved in the reaction by XRD , XPS , and EPR , the reaction mechanism was elucidated. The experimental results indicated that the removal products were mainly sulfates and nitrates. The free radicals involved in the reaction were SO 4 ·− , ·OH, and Cl·, and the key free radical was Cl·.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2016
·
IF 4.312
Kun Jiang,Dong Sheng,Zihao Zhang,Jie Fu,Zhaoyin Hou,Xiuyang Lu
Mixed MgO–Al 2 O 3 (with different Mg/Al ratio) supported nickel catalysts were prepared via co-precipitation method and used for hydrogenation of levulinic acid to γ-valerolactone under mild condition. Characterization results indicated that mixed MgO–Al 2 O 3 supported Ni catalysts possessed bigger surface area than that of Ni/MgO and Ni/Al 2 O 3 , and Ni dispersed highly on the surface of mixed MgO–Al 2 O 3 support. It was found that mixed MgO–Al 2 O 3 supported Ni catalysts were more active and selective for the hydrogenation of levulinic acid to γ-valerolactone than that of Ni/MgO and Ni/Al 2 O 3 , and the best yield of γ-valerolactone at 160 °C, 1 h and 3 MPa H 2 reached 99.7% over Ni/MgAlO 2.5 , and Ni/Mg 2 Al 2 O 5 could be recycled without obvious loss of its initial activity.
研究领域:
化学工程
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Junshen Zhang,Juan Luo,Jiashan Chen,Ziyan Xu,Yuyu Chen,Han Yan,Rui Ma,Shichang Sun
MgO’s great potential for capturing CO 2 has drawn a lot of attention, but the limited O 2– sites prevents its further development. This work proposed a microwave-induced method (microwave hydrothermal and microwave sintering) to produce high-performance MgO CO 2 adsorbent and was further modified using carbonates (K 2 CO 3 ) and nitrates of alkali metals (NaNO 3 , KNO 3 ). The outcomes demonstrated that the small particle size MgO nanocrystals (6.20 nm) with a CO 2 uptake of 1.8 mmol·g −1 could be produced by a unique method of microwave heating from the inside out. Among the modified samples, addition of 20 mol% NaNO 3 on the surface of MgO exhibited the highest CO 2 uptake (11.91 mmol·g −1 ), and the uptake was still 7.9 mmol·g −1 after 10 cycles. The addition of molten salt changed the adsorbent’s active sites, resulting in an increase in O 2– alkaline sites and the activation of MgO lattice defects, both of which improved the sample’s CO 2 adsorption performance. This work could offer a new idea for creating affordable and effective CO 2 solid adsorbents to capture CO 2 .
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Changqing Gui,Zirui Wang,Changjian Ling,Zhongfeng Tang
Molten salt-doped MgO adsorbent is considered one of the most promising CO 2 adsorbents in the field. In this work, MgO-based adsorbents were prepared by one-step calcination using MgCl 2 ·6 H 2 O as magnesium source. The CO 2 adsorption performance of MgO-based adsorbents was investigated via different methods. Results showed that the maximum CO 2 adsorption capacity of MgO doped by LiNO 3 -NaNO 3 -KNO 3 was 57.1% at the CO 2 concentration of 80% and 350 ℃, and the MgO-based adsorbents showed good regeneration. The nanosheet structure of the MgO-based adsorbents decreased with the increase in the number of cycles, whereas the crystal structures of MgO and alkali metal nitrates did not change because of multiple decarbonization. DFT computation revealed selective adsorption of CO 2 on different crystal faces of MgO. The (200) crystal face of molten salt-doped MgO did not have CO 2 trap ability. In addition, the doped nitrate did not directly participate in the reaction but reduced the adsorption energy of MgO carbonation. The adsorption energies of the MgO (220) and (222) crystal faces after doping with nitrate were reduced to − 2.07 and − 3.26 eV, respectively. The overall energy level of adsorption decreased as the number of resonance peaks and the stability of the structure increased. This study explains why MgO currently fails to reach the theoretical adsorption capacity and reveals the underlying mechanism of molten salts.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Journal of the Australian Ceramic Society
·
2019
·Vol. 56
·期 3
·895-903
·
IF 0.692
Ma Jing-Yi,Zhang Yi-Bing,Wang Jun-Xia,Song Yu-Yang,Zhou Tong,Wang Yan,Wang Hao-Yu,Wang Jin
In the present paper, the ordered Nd 2 Zr 2 O 7 pyrochlore was primarily synthesized by flux method and the MgO-Nd 2 Zr 2 O 7 composite ceramics were fabricated subsequently through a conventional sintering route. A suite of characterization techniques, including XRD, Raman and BSE-EDS were employed to investigate the phase composition and microstructure of the as-prepared Nd 2 Zr 2 O 7 and MgO-Nd 2 Zr 2 O 7 samples. The acid solubility of the MgO-Nd 2 Zr 2 O 7 composite ceramics was also tested. XRD results showed that the ordered Nd 2 Zr 2 O 7 pyrochlore can be synthesized when the calcination temperature is in the range of 850–1200 °C. Raman results suggested that the chemical bonds of Nd 2 Zr 2 O 7 pyrochlore get stronger, and more ordered structure can be gradually formed with the increase of calcining temperature. For the MgO-Nd 2 Zr 2 O 7 composite ceramics, XRD results also showed that the Nd 2 Zr 2 O 7 phase in the composite ceramics presents higher crystallinity degree and no other phase is formed after sintering at 1400–1550 °C. Moreover, BSE-EDS results indicated that the MgO-Nd 2 Zr 2 O 7 composite ceramics are compact and dense, and the MgO and Nd 2 Zr 2 O 7 phases are almost uniformly distributed between each other. In addition, the relative density of the bulk ceramics was about 96–98%, and it was concluded that ≥ 1500 °C could be the suitable sintering temperature to produce MgO-Nd 2 Zr 2 O 7 composite ceramics. At last, the dissolution behavior of the ceramics in nitric acid solution revealed that only MgO in the MgO-Nd 2 Zr 2 O 7 composite ceramics can be dissolved in the 11 M HNO 3 solution within 24 h, and the dissolution rate was relatively low because of the high densification of the sample.
研究领域:
材料科学
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核能工程
·
化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Jiaojiao Tan,Jiaming Wang,Ziyang Zhang,Zhi Ma,Luhui Wang,Yuan Liu
To improve the catalytic activity of CO 2 methanation at low temperature, a series of Ni/ZrO 2 catalysts with different Ni loadings were prepared by citrate complexing method. Based on the optimal Ni loading of 6 wt%, a certain amount of MgO was doped to improve the thermal stability of Ni/ZrO 2 catalyst. When Ni/Mg molar ratio was 4, there was the best performance, getting as high as 90% CO 2 conversion and nearly 100% CH 4 selectivity at 250 °C, 0.1 MPa and a WHSV of 15,000 ml g −1 h −1 , and the equilibrium CO 2 conversion was obtained at 300 °C. XRD , BET, TPR, CO 2 -TPD, H 2 -TPD, XPS , TG and TEM were conducted to investigate the reason of high activity of Ni/ZrO 2 catalyst at low temperature and the effect of doping MgO. Results suggested that highly dispersed Ni nanoparticles are responsible for the excellent catalytic activity. MgO can effectively improve stability of Ni-based catalysts by the confinement effect. Meanwhile, it is also found that there are little improvements on catalytic activity after doping MgO, and the TOF of catalysts with different MgO doping is basically the same, indicating CO 2 can be efficiently adsorbed and activated on the monoclinic ZrO 2 , and MgO do not contribute to the intrinsic activity.
研究领域:
催化
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2015
·
IF 3.942
Jun Chen,Shuanghong Tian,Jiang Lu,Ya Xiong
This study aims to provide a direction to tailor catalytic activity of catalyst by selectively exposing a crystal facet. Herein three sheet-like MgO materials with the primarily exposed crystal facet of (1 1 1), (1 1 0), (2 0 0) were prepared, respectively. Results show that the catalytic ozonation on each MgO substantially enhanced the removal of 4-chlorophenol and total organic carbon when compared with ozonation alone or that on traditional MgO. The pseudo first-order reaction constant of 4-chlorophenol removal in ozonation catalyzed by MgO(1 1 1), MgO(1 1 0), MgO(2 0 0) is 4.8, 2.5, 3.1 times higher than that in the single ozonation, respectively. When different dosage but the same surface area of MgO was applied, their catalytic activities changed as MgO(1 1 1) > MgO(1 1 0) > MgO(2 0 0). It indicates that the catalytic activity significantly depends on the crystal facet besides the surface area. That is because the drawbacks, such as edges, steps, and kinks, on each facet decreased in the order of (1 1 1) > (1 1 0) > (2 0 0). CO 2 -TPD and zeta potential measurement show that the drawbacks caused more and stronger surface basic groups in the form of hydroxyl and isolated oxygen due to the availability of more unsaturated coordination sites. These active basic centers make the easy formation of basic microenvironment near MgO particles and thus favor the ozonation. Finally, the catalytic mechanism was explored and compared by evaluating the ozone decomposition, qualitatively and quantitatively identifying hydroxyl radicals, and determining the ozone utilization efficiency. It reveals that MgO with more surface basic groups can enhance the transformation rate of ozone to hydroxyl radicals more efficiently. All these results show that MgO is a very potential ozonation catalyst and the catalytic activity can be tailored by exposing crystal facet with more drawbacks.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Hongjie Cui,Qiming Zhang,Yuanwu Hu,Chong Peng,Xiangchen Fang,Zhenmin Cheng,Vladimir V. Galvita,Zhiming Zhou
As a potential candidate for precombustion CO2 capture at intermediate temperatures (200–400 °C), MgO-based sorbents usually suffer from low kinetics and poor cyclic stability. Herein, a general and facile approach is proposed for the fabrication of high-performance MgO-based sorbents via incorporation of CaCO3 into MgO followed by deposition of a mixed alkali metal salt (AMS). The AMS-promoted MgO–CaCO3 sorbents are capable of adsorbing CO2 at an ultrafast rate, high capacity, and good stability. The CO2 uptake of sorbent can reach as high as above 0.5 gCO2 gsorbent–1 after only 5 min of sorption at 350 °C, accounting for vast majority of the total uptake. In addition, the sorbents are very stable even under severe but more realistic conditions (desorption in CO2 at 500 °C), where the CO2 uptake of the best sorbent is stabilized at 0.58 gCO2 gsorbent–1 in 20 consecutive cycles. The excellent CO2 capture performance of the sorbent is mainly due to the promoting effect of molten AMS, the rapid formation of CaMg(CO3)2, and the plate-like structure of sorbent. The exceptional ultrafast rate and the good stability of the AMS-promoted MgO–CaCO3 sorbents promise high potential for practical applications, such as precombustion CO2 capture from integrated gasification combined cycle plants and sorption-enhanced water gas shift process.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Science
·
2017
·Vol. 4
·期 9
·1700031
·
IF 9.034
Junjie Ma,Guang Yang,Minchao Qin,Xiaolu Zheng,Hongwei Lei,Cong Chen,Zhiliang Chen,Yaxiong Guo,Hongwei Han,Xingzhong Zhao,Guojia Fang
Reducing the energy loss and retarding the carrier recombination at the interface are crucial to improve the performance of the perovskite solar cell (PSCs). However, little is known about the recombination mechanism at the interface of anode and SnO 2 electron transfer layer (ETL). In this work, an ultrathin wide bandgap dielectric MgO nanolayer is incorporated between SnO 2 :F (FTO) electrode and SnO 2 ETL of planar PSCs, realizing enhanced electron transporting and hole blocking properties. With the use of this electrode modifier, a power conversion efficiency of 18.23% is demonstrated, an 11% increment compared with that without MgO modifier. These improvements are attributed to the better properties of MgO-modified FTO/SnO 2 as compared to FTO/SnO 2 , such as smoother surface, less FTO surface defects due to MgO passivation, and suppressed electron–hole recombinations. Also, MgO nanolayer with lower valance band minimum level played a better role in hole blocking. When FTO is replaced with Sn-doped In 2 O 3 (ITO), a higher power conversion efficiency of 18.82% is demonstrated. As a result, the device with the MgO hole-blocking layer exhibits a remarkable improvement of all J–V parameters. This work presents a new direction to improve the performance of the PSCs based on SnO 2 ETL by transparent conductive electrode surface modification.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RADIATION PHYSICS AND CHEMISTRY
·
2023
·
IF 2.9
Wenwen Shan,Baohe Yuan,Yong Zhang
A series of polydopamine (PDA) modified MgO@Bi 2 O 3 composites (MB/PDA) with different mass ratios were fabricated to remove soluble U(VI). Batch experiments showed that MB/PDA-2 was provided with better adsorption performance than MB/PDA-1 and MB/PDA-3 and the maximum adsorption amount (C 0 = 10 mg/L, m/v = 0.1 g/L, pH = 4.0 and T = 298 K) reached 465.8 mg/g within 80 min. Moreover, over 95% U(VI) was removed by MB/PDA-2 in the process of dynamic adsorption and MB/PDA-2 still displayed high adsorption percentage (75%) after five cycles. The electrostatic attraction, complexation, redox reaction and cation-π interaction apparently influenced the U(VI) capture performance on MB/PDA-2. In short, MB/PDA-2 with high adsorption capacity was a preeminent material to extract soluble U(VI).
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Zijun Peng,Xudong Luo,Zhipeng Xie,Mengmeng Yang
SiO 2 -MgO ceramics containing different weight fractions (0, 0.5, 1, 2, and 4 wt%) of SiO 2 powder were prepared by mixing nano MgO powder, and the powder mixtures were densified by spark plasma sintering (SPS). The effect of SiO 2 addition and SPS method on the sintering behavior, microstructure and mechanical properties were investigated. Results were compared to specimens obtained by conventional hot pressing (HP) under a similar sintering schedule. The highest relative density, flexural strength and hardness of 2 wt% SiO 2 -MgO ceramics reached 99.98%, 253.99 ± 7.47 MPa and 7.56 ± 0.21 GPa when sintered at 1400 °C by SPS, respectively. The observed improvement in the sintering behavior and mechanical properties are mainly attributed to grain boundary "strengthening" and intragranular "weakening" of the MgO matrix. Furthermore, the spark plasma sintering temperature could be decreased by more than 100 °C as compared with the HP method, SPS favouring enhanced grain boundary sliding , plastic deformation and diffusion in the sintering process.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
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
·
催化化学
·
能源工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）