Desalination and Water Treatment
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2024
·
IF 1
Jing Yang,Siyuan Yang,Jing Zhang,Jian He,Wei Jiang
ABSTRACT The recovery of Cr(VI) from the solution and the utilization of by-products are significant for waste-water treatment and environmental protection. In this study, the amorphous ZrO 2 was prepared using a solvothermal method and used to treat the wastewater containing Cr(VI). Amorphous ZrO 2 is effective for the photocatalytic reduction of Cr(VI). Without a sacrificial agent, 20 mL potassium dichromate solution (20 mg/L) is reduced to almost 0 mg/L within 10 min. Moreover, the by-products obtained from this process exhibit good performance in the catalytic dehydrogenation of ethane coupled with the reverse water–gas reaction. The maximum yield of ethylene is 12.9%, and the service life of the catalyst reached 160 min. Catalyst deactivation is caused by carbon deposition, and the deactivated catalyst is regenerated by roasting in the air. The feasibility of this green process is demonstrated, including the one-step photocatalytic reduction of Cr(VI) and utilization of the by-product as an ethane dehydrogenation catalyst.
研究领域:
环境科学
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催化化学
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DOI
高影响因子
Catalysts
·
2018
·Vol. 8
·期 8
·296
·
IF 3.465
Shuqi Fang,Kang Bi,Qiao Zhang,Lingpeng Chen,Yongming Sun,Hongyu Huang,Longlong Ma,Chenguang Wang
Layered double hydroxide (LDH) is a layered solid containing positively charged layers with negatively charged anions as an interchangeable interlayer. In this research, Mg(Al)O supports were synthesized with three different Mg:Al molar ratios, and bimetallic PtSn catalysts were loaded onto the supports via the anion exchange method. The properties of ethane dehydrogenation of the PtSn/Mg(Al)O catalysts were investigated. The results show that the structure and properties of the PtSn/Mg(Al)O catalysts were influenced by the Mg:Al molar ratio of the hydrotalcites, which consequently influenced the ethane dehydrogenation performance. When the Mg:Al ratio was 5:1, the ethane dehydrogenation performance was optimal, relative to the Mg:Al ratios of 2:1 and 10:1.Keywords:hydrotalcite;Mg:Al molar ratio;anion exchange method;ethane dehydrogenation
研究领域:
催化
·
化学工程
·
材料科学
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产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2021
·Vol. 152
·期 5
·1372-1385
·
IF 3.186
Qiu Baocheng,Zhang Yakun,Zhang Yi
The rapid deactivation caused by coke deposits is the major obstacle to the ethane aromatization of Zn-based catalysts. We have successfully synthesized a Zn-embedded inside HZSM-5 crystal catalyst (Zn@HZSM-5) by hydrothermal synthesis using preformed Zn/SiO 2 as the only silicone source. Based on various characterization results, including in situ etching XPS, operando DRIFTS, as well as NMR, it is found that Zn(OH) + and [Zn–O–Zn] 2+ species are active sites for ethane aromatization for zinc-based catalysts, and their dynamic transformation significantly changes reaction performance of ethane dehydrogenation. For the Zn/HZSM-5 catalyst, the existence of a large number of [Zn–O–Zn] 2+ species causes higher initial ethane conversion and higher selectivity of aromatics, resulting in a large amount of coke deposits. Moreover, [Zn–O–Zn] 2+ species on the Zn/HZSM-5 catalyst fast transit to Zn(OH) + species and subsequently form the sintered ZnO species, leading to rapid deactivation. For the Zn@HZSM-5 catalyst, the embedded structure contributes to forming more Zn(OH) + species and delays the transformation of the Zn(OH) + species to [Zn–O–Zn] 2+ species, resulting in slowly increased selectivity of aromatics during the reaction. Therefore, the Zn@HZSM-5 catalyst realizes stable ethane conversion with dynamic selectivity. Graphic Abstract
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2018
·
IF 3.956
Tian-qi Lei,Yan-hu Cheng,Chang-xi Miao,Wei-ming Hua,Ying-hong Yue,Zi Gao
Dehydrogenation of ethane to ethylene in the presence or absence of CO 2 over silica-doped TiO 2 supported Ga 2 O 3 catalysts was investigated. The silica doping of TiO 2 support greatly improved the dehydrogenation activity in the absence of CO 2 , which can be ascribed to the increased acid sites. The initial activity in the presence of CO 2 decreased after the silica doping, due to the reduction in reverse water-gas shift ability. However, the selectivity as well as the stability increased, resulting in higher steady ethylene yield. A dynamic process consisting of alternative oxidative dehydrogenation/regeneration cycles by gasifying the carbon deposit with air for 10 min after each cycle of 6 h reaction was also performed and relatively stable ethane conversion ~30% and ethylene yield ~25% can be achieved. The different catalytic behaviors are probably associated with the different state of gallium species, caused by the different interaction between the Ga 2 O 3 and support.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMISTRY
·
2021
·Vol. 40
·期 8
·918-924
·
IF 6
Jisheng Xu,Chengxiang Shi,Shuguang Zhang,Qiancheng Zheng,Lun Pan,Xiangwen Zhang,Ji-Jun Zou
Comprehensive Summary Non-oxidative ethane dehydrogenation is a promising route to produce ethene. Herein, PtSn supported catalysts were investigated to achieve better ethane dehydrogenation performance by introduction of different Zr promoters, i.e. , framework Zr and ZrO 2 , to mesoporous MCM-41. In-situ XRD, TEM and CO chemisorption show that aggregation of metal particles and phase segregation of Pt 3 Sn to Pt and PtSn 3 at high temperature occur for PtSn/M, leading to bad ethane dehydrogenation activity. Strong interaction between ZrO 2 and PtSn species, as proved by XPS, results in restrained metal particles, which promotes the initial reactivity. However, Pt phase generated on surface is disadvantageous for the desorption of produced ethene as indicated by CO-IR and C 3 H 6 -TPD, and pyridine-IR and NH 3 -TPD indicate strong acidity generated. Both deactivate the catalyst rapidly by deep dehydrogenation and coking. Moderate interaction between PtSn species and Si-O-Zr with much weaker acidity is formed when framework Zr is incorporated into MCM-41, which benefits the dispersion of metal particles, formation of Pt 3 Sn/Pt species and stabilization of metal species from phase segregation. Outstanding initial ethane conversion and ethene selectivity of ca. 99% were achieved for the optimal PtSn/ZrM, which is more coking-tolerant and stable by generating graphitic carbon mainly on support instead of active metals.
研究领域:
催化化学
·
材料科学
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产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2023
·
IF 2.8
Zhang Yakun,Xu Lin,Wang Wen,Wu Qing,Zhang Yi
The efficient conversion of ethane has attracted more and more attention because of the shale gas revolution. The coupling of ethane dehydrogenation (EDH) and benzene alkylation over the 1.5Pt/HZSM-5 realize high activity close to the thermodynamic equilibrium of EDH at 500 ℃ and 0.9 bar ethane partial pressure. Meanwhile, the coupled reaction shows long-term stability during 22 h with a slightly decreased ethane conversion of 0.03% per hour and as high as 42% selectivity of ethylbenzene. Based on various characterization, including XRD, HR-TEM, NH 3 -TPD, Py-IR, TGA, it is confirmed that the coupling reaction could convert ethylene, formed by EDH over Pt sites, to ethylbenzene via benzene alkylation over Brönsted acidic sites (BAS) subsequently, and suppressing the sintering of Pt species and coke deposition induced by aromatization and deep dehydrogenation, resulting in high activity and long-time steady state. Graphical Abstract
研究领域:
化学工程
·
催化化学
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Changjun Liu,Yingming Zhu,Kequan Mu,Qiang Liu,Hairong Yue,Wei Jiang
This work presents a strategy to convert the Cr(VI) pollutant in wastewater into active Cr catalysts in one step by simultaneous photoreduction and deposition using ZrO2 nanoparticles as the photocatalyst and support. Both highly dispersed Cr(0) and Cr2O3 were found on the surface of the resultant Cr/ZrO2 catalyst after UV irradiation. After photoreduction treatment, no residual chromium was detected in post-treated water. The resultant Cr/ZrO2 was found to be an active catalyst for selective dehydrogenation of ethane. It is slightly more stable and active than that prepared by the impregnation method. The interconversion between the structures of Cr–O–Cr and Cr═O should be the active site for oxidative dehydrogenation of C2H6 with CO2. An ethylene yield as high as 17.0% was achieved at 650 °C. This work proved that producing supported metal catalysts from the corresponding metal contaminated wastewater via proper one-step procedure, such as photoreduction treatment, is a feasible strategy to meet the ever-increasing stringent environmental requirements with better economic efficiency.
研究领域:
环境科学
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催化化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Baocheng Qiu,Yakun Zhang,Yi Liu,Yi Zhang
The efficient conversion of ethane has become more attractive recently because of the shale gas revolution. Platinum-based catalyst is the most active for direct dehydrogenation of ethane to ethylene, but it always suffers deactivation due to coke deposition and sintering of supported Pt. We have successfully synthesized a Pt-embedded inside HZSM-5 crystal catalyst (Pt@HZSM-5) by hydrothermal synthesis using Pt/SiO 2 as only silicone source, to realize excellent stability during the dehydrogenation of ethane (EDH) to ethylene. Based on various characterization results, including in-situ synchrotron XANES and EXAFS, in situ XPS, operando DRIFTS, as well as 27 Al MAS NMR, the stable Pt species with high electron density on Pt@HZSM-5 avoids the deep dehydrogenation of ethane to form coke, and the surrounding environment of Pt active phase, including newly formed HZSM-5 frameworks and its acidity, contributes to suppressing the aromatization of the formed ethylene. As synergic effects, the Pt@HZSM-5 catalyst realizes excellent stability during 50 h EDH reaction without any regenerations with relatively high ethane conversion under the serve reaction conditions (90% ethane in feed gas, 0.1 MPa, 550 °C). However, the conventional Pt/HZSM-5 catalyst exhibits dynamic transformation of Pt chemical state, particle size, and its surrounding environment, resulting in rapid deactivation induced by much more carbon deposition and aromatization of the formed ethylene.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
ACS Catalysis
·
2021
·
IF 13.084
Yuebing Xu,Wenda Yu,Hao Zhang,Jian Xin,Xiaohui He,Bing Liu,Feng Jiang,Xiaohao Liu
Various Co-based SAPO-34 catalysts were prepared using different methods, including ion exchange (IE), incipient-wetness impregnation (IWI), and solid-phase grinding (SPG), to correlate the chemical states of Co species with the C–H and C–C bond scissions in ethane dehydrogenation. The IE-prepared Co/SAPO-34 led to stable, unreducible, and isolated exchanged Co sites anchored on the zeolite framework with a structure of −AlF–O–Co–O– and showed the highest selectivity to ethylene of close to 98% at 600 °C, which suggests that these Co sites favors suppressing the C–C bond scission in ethane. In comparison, the IWI- and SPG-prepared Co/SAPO-34 catalysts, especially for those with a high Co loading, inevitably give Co oxide clusters that are easily reduced into metallic Co. Together with catalytic results, characterizations, and DFT calculations, it is confirmed that the reduced Co clusters, especially for those outside SAPO-34 channels without the confinement effect, favor both C–H and C–C bond scission, boosting the conversion of ethane into CH4 or/and coke; however, the ionic-state −Co–O– species can smoothly terminate the ethane dehydrogenation for the ethylene product due to relatively high energy barriers for both C–H and C–C bond scission, avoiding a deep dehydrogenation and C–C cracking. As expected, the unreducible −Co–O– sites are very stable in the title reaction without deanchoring from the zeolite framework in a 100 h cyclic test. This study not only demonstrates the stable −Mδ+–Oδ− structure favorable for suppressing C–C bond scission but also highlights a catalyst-constructing strategy for Co-based and similar metal-based catalysts for dehydrogenation of other light alkanes.
研究领域:
催化化学
·
材料科学
·
计算化学
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产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2022
·Vol. 12
·期 12
·3874-3885
·
IF 6.177
Ling Zhang,Jikai Sun,Shuchao Jiang,Huijie He,Guoqing Ren,Dong Zhai,Rui Tu,Shengliang Zhai,Tie Yu
This work reported an efficient PdIr/activated carbon (PdIr/AC) catalyst and its application during direct ethane dehydrogenation (EDH) into ethane. The XRD and HADDF-STEM results revealed Pd/Ir nano-particles and atomically dispersed Pd2+ and Ir4+ species simultaneously. The activity tests demonstrated that Ir species showed higher C2H4 selectivity than Pd species and the co-presence of Pd/Ir could further improve the catalytic stability and inhibit carbon deposition over the bimetallic Pd/Ir catalyst. Nevertheless, raising the reaction temperature from 500 °C to 600 °C boosted coking including carbon nanotubes (CNTs) and carbon particles. XPS results of Pd7Ir2/AC-B after Ar or H2 pretreatment proved that the active sites are Pd2+/Ir4+ species. The simulation results exposed the reaction pathway over Ir4+/Pd2+ species, and ethane dehydrogenation was the rate-determining step over the PdIr/AC sample; meanwhile, the synergetic effect between Pd2+ and Ir4+ increased their TOF (C2H4). Finally, a deactivation mechanism was also proposed to examine the coking over various metal species.
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
Chem
·
2022
·
IF 25.832
Lu Liu,Huan Li,Hang Zhou,Shengqi Chu,Lujie Liu,Zhaochi Feng,Xuedi Qin,Jizhen Qi,Jue Hou,Qinming Wu,Hangjie Li,Xi Liu,Liwei Chen,Jianping Xiao,Liang Wang,Feng-Shou Xiao
Summary Catalytic dehydrogenation of ethane (EDH) is promising for the utilization of shale gas to produce ethylene, but the current processes mostly exhibit space-time productivity of ethylene lower than 1.5 Kg C2H4 Kg cat −1 h −1 because of the insufficient catalyst activity in the non-oxidative route. We reported a catalyst with isolated cobalt in siliceous zeolite derived from a mechanically assisted spontaneous dispersion. This material can operate as a non-oxidative EDH catalyst at thermodynamically limited conversion levels under rapid gas feeding, resulting in ethylene productivity at 13.4 Kg C2H4 Kg cat −1 h −1 . This result is superior to that of the previous non-noble metal catalysts and even outperforms the precious PtSn/Al 2 O 3 catalyst. The isolated cobalt sites are preserved upon calcination at high temperatures and during EDH operation under harsh conditions, resulting in superior durability in a long reaction period with negligible coke formation.
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
RARE METALS
·
2025
·
IF 11
Luo Jun,Ke Yan-Dong,Li Qi-Yue,Tian Ying-Fa,Dong Bing-Hai,Yan Dong,Li Jian,Li Oi-Lun,Jia Li-Chao
Ethylene (C 2 H 4 ) is conventionally produced by a high energy-consumption process based on the steam cracking of ethane (C 2 H 6 ). In contrast, we presented a novel symmetrical solid oxide fuel cell (SOFC) to co-produce electricity and C 2 H 4 through C 2 H 6 dehydrogenation. The symmetrical cell contains a thin BaZr 0.1 Ce 0.7 Y 0.2 O 3 (BZCY) electrolyte sandwiched between two thicker (PrBa) 0.95 (Fe 0.7 Ni 0.2 Cu 0.1 ) 1.8 Mo 0.2 O 6- δ impregnated BZCY (PBFNCM-BZCY) electrodes. The as-synthesized reduced-PBFNCM (R-PBFNCM) contained Fe–Ni–Cu alloy particles embedded on a double-perovskite matrix uniformly, while the electrode showed high oxygen vacancy concentration, electronic conductivity, redox stability, and activity for C 2 H 6 dehydrogenation with improved ethylene selectivity. The symmetrical cell demonstrated a peak power density of 409 mW cm −2 using C 2 H 6 as fuel, accompanying with a C 2 H 6 conversion of 51.2%, a C 2 H 4 selectivity of 92.5%, and a C 2 H 4 yield of 47.4% at 750 °C and 750 mA cm −2 . Despite carbon deposition occurred slowly in the anode, the deposited carbon was removed by simply switching C 2 H 6 and air between electrodes. Consequently, the cell voltage and C 2 H 4 yield recover by 91.4% and 98.1%, respectively, after three switches with an interval of 48 h, suggesting that the symmetrical SOFC is a promising solution for long-term continuous electricity and C 2 H 4 co-production by C 2 H 6 dehydrogenation. Graphical
研究领域:
能源材料科学
·
化学工程
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）