CHINESE JOURNAL OF CATALYSIS
·
2022
·
IF 12.92
Zhaopeng Liu,Youming Ni,Zhongpan Hu,Yi Fu,Xudong Fang,Qike Jiang,Zhiyang Chen,Wenliang Zhu,Zhongmin Liu
The utilization of metal oxide-zeolite catalysts in the syngas-to-olefin reaction is a promising strategy for producing C 2 –C 4 olefins from non-petroleum resources. However, the effect of the crystal phase of metal oxides on the catalytic activity of these oxides is still ambiguous. Herein, typical metal oxides (ZnO/ZrO 2 ) with different crystal phases (monoclinic ( m -ZrO 2 ) and tetragonal ( t -ZrO 2 )) were employed for syngas conversion. The (ZnO/ m -ZrO 2 +SAPO-34) composite catalyst exhibited 80.5% selectivity for C 2 –C 4 olefins at a CO conversion of 27.9%, where the results are superior to those (CO conversion of 16.4% and C 2 –C 4 olefin selectivity of 76.1%) obtained over (ZnO/ t -ZrO 2 +SAPO-34). The distinct differences are ascribed to the larger number of hydroxyl groups, Lewis acid sites, and oxygen defects in ZnO/ m -ZrO 2 compared to ZnO/ t -ZrO 2 . These features result in the formation of more formate and methoxy intermediate species on the ZnO/ m -ZrO 2 oxides during syngas conversion, followed by the formation of more light olefins over SAPO-34. The present findings provide useful information for the design of highly efficient ZrO 2 -based catalysts for syngas conversion.
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
INDUSTRIAL CROPS AND PRODUCTS
·
2019
·
IF 4.191
Xiaoyun Li,Jiaxin Yang,Rui Xu,Lefu Lu,Fangong Kong,Min Liang,Lijie Jiang,Shuangxi Nie,Chuanling Si
The production of platform chemicals from lignocellulosic biomass is scientifically valuable but technologically challenging. With the aim to establish a green reaction system for the production of furfural from lignocellulosic biomass, in the current work, H-SAPO-34 was investigated for catalysis of the conversion of Eucalyptus sawdust to furfural in γ-valerolactone (GVL). H-SAPO-34 was prepared and characterized by XRD, SEM, FTIR, BET, TGA and ammonia adsorbed FTIR. H-SAPO-34 possesses Brønsted and Lewis acid sites and a large specific surface area. The average pore diameter of H-SAPO-34 was 0.86 nm, which is beneficial for the spread of xylose and furfural and the inhibition of humin production. In this work, a peak furfural yield of 99.28% from Eucalyptus was achieved at 210 °C in 120 min with 30 g/L H-SAPO-34. The Brønsted/Lewis acid bifunctionality and the solvent effect of γ-valerolactone possibly contributed to the high furfural yield from real biomass. The kinetics of the conversion of Eucalyptus sawdust to furfural was also studied, and the activation energy for furfural production was calculated. Additionally, the catalytic activity and stability of the regenerated catalyst were estimated.
研究领域:
化学工程
·
可再生资源与环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Fanhui Meng,Lina Wang,Muhammad Asif Nawaz,Qian Wang,Zhiyuan Gong,Zhong Li
Direct conversion of syngas to light hydrocarbons has been intensively studied in recent years; however, the high selectivity of light hydrocarbons is still a challenging task to achieve a high CO conversion. Here, a bifunctional catalyst consisting of a methanol synthesis catalyst (CZA) and a methanol to dimethyl ether (DME) catalyst (Al 2 O 3 ) was employed with a hydrocarbon synthesis catalyst (SAPO-34), for syngas conversion to light hydrocarbons in a dual fixed-bed reactor. The conversion of simulated intermediates CO/CO 2 /DME/N 2 /H 2 with a molar ratio of 9/6/4/5/76, obtained from syngas conversion to DME over CZA and Al 2 O 3 , was studied over SAPO-34 zeolites. It was found that SP34-0.1 with Si/Al ratio of 0.1, exhibited low amount of strong acid (0.60 mmol/g) and high selectivity to light olefins (74.1%), while SP34-0.4 with Si/Al ratio of 0.4 exhibited high amount of strong acid (1.00 mmol/g) leading to high selectivity of light paraffins (88.4%). The in-situ DRIFTS analysis illustrated that DME can be rapidly adsorbed on the hydroxyl site of SAPO-34 and decomposed into the surface methyl species, where SP34-0.4 could produce more dimethylcyclopentenyl cationic species than SP34-0.1. It was suggested that the overall reaction route led to a high selectivity to light olefins (84.2%) with a CO conversion of 61.2% on (CZA + Al 2 O 3 ) catalyst combined with SP34-0.1, while a high selectivity to light paraffins (76.3%) could be achieved by combining with SP34-0.4 at 70.3% CO conversion. Since, the current study interprets that the selectivity of hydrocarbons can be adjusted by regulating the acidity of SAPO-34 to achieve a high CO conversion in the dual fixed-bed reactor scheme.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Xiaoming Zhou,Zhuoyuan Chen,Zhiyong Guo,Haiping Yang,Jingai Shao,Xiong Zhang,Shihong Zhang
A series of dual metal incorporated CuCex-SAPO-34(x = 0–0.04) samples were synthesized using one-pot hydrothermal method with diethylamine as organic structure-directing agent for selective catalytic reduction of NO x by NH 3 . The catalytic properties were elucidated in detail with physicochemical properties being analyzed using various instruments. All the catalysts exhibited typical SAPO-34 crystal structures with high specific surface areas. With the dual-metal incorporation, the surface acidity and amount of isolated Cu 2+ , which may be active sites for NH 3 -SCR, were significantly enhanced. However, excessive Ce restrained the formation of isolated Cu 2+ due to its occupation of cationic sites. Therefore, the 0.05CuCe0.02-SAPO-34 exhibited high NO conversion (≥80%) at 168°C-500°C. Furthermore, the NH 3 -SCR mechanism over different catalysts was investigated in-situ DRIFTS experiments. For the 0.05Cu-SAPO-34, the adsorbed NH 3 species react with gaseous NO and following the E-R mechanism throughout the reaction temperature range. Meanwhile, adsorbed NO 2 was detected and reacted with the adsorbed NH 3 species according to the L-H mechanism in low-temperature region. In contrast, the NH 3 -SCR reaction over the 0.05CuCe0.02-SAPO-34 primarily followed the E-R mechanism throughout the temperature range. The L-H mechanism was cut off due to the loss of the adsorption ability of nitrous species at high temperatures., resulting in NO conversion decreasing.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysis Science & Technology
·
2019
·Vol. 9
·期 22
·6438-6451
·
IF 5.726
Lina Zhang,Haiyan Liu,Yuanyuan Yue,Unni Olsbye,Xiaojun Bao
This article reports a novel strategy to design and synthesize hierarchical SAPO-34@kaolin composites as catalysts for methanol to olefins. This strategy includes two key steps: the first is the top-down depolymerization of kaolin microspheres into active silicon and aluminium species via thermal treatment, and the second is the bottom-up rearrangement and reorganization of the resulting active silicon and aluminium species and the external phosphorous source into hierarchical SAPO-34@kaolin composites both outside and inside the calcined kaolin microspheres which are co-templated by hexadecyltrimethyl-ammonium bromide (CTAB) and 3-(trimethoxysilyl)propyl dimethyl octadecyl ammonium chloride (TPOAC). It was found that CTAB functions as an in situ growth promoter to increase the SAPO-34 content in the resulting composites. Meanwhile, TPOAC serves as a mesoporogen to generate mesopores in the SAPO-34 phase of the SAPO-34@kaolin composites, and both CTAB and TPOAC play the role of a crystal growth inhibitor leading to the formation of SAPO-34 with a small crystal size. Distinctly different from the semi-synthesis products that were obtained by physically mixing and binding SAPO-34 with kaolin in appropriate proportions, the SAPO-34@kaolin composite synthesized involving both CTAB and TPOAC exhibits outstanding performance in methanol to olefins, with the selectivity to ethylene and propylene being increased by 20% and the catalyst lifetime being remarkably prolonged from 50 to 200 min. This is attributed to the high content, small crystal size, and hierarchical micro-mesoporous structure of the SAPO-34 crystallites in the composites.
研究领域:
催化化学
·
材料科学
·
能源化工
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2023
·Vol. 25
·期 4
·1395-1405
·
IF 9.8
Pengfei Wu,Miao Yang,Jifeng Pang,Dong Fan,Lei Song,Tantan Sun,Mingyuan Zheng,Peng Tian,Tao Zhang
The conversion of biomass resources into 5-hydroxymethylfurfural (5-HMF) is of great significance for the valorization of biomass into key chemicals and fuels. However, designing heterogeneous catalysts with controllable Brønsted and Lewis acid sites for achieving high yields of 5-HMF remains a challenge. Herein, a highly efficient SAPO-34 nanocrystallites catalyst has been synthesized by a facile strategy, employing commercial low-cost organosilane [3-glycidoxypropyltrimethoxysilane (AC-230)] together with seeds and microporous template triethylamine. The complex functionalities of AC-230 were investigated by conditional experiments and systematic characterizations. The resultant SAPO-34 nanocrystallites (SP-MS) have an ultra-high external surface area (180 m2 g−1), large mesopore volume (0.51 cm3 g−1), a high amount of accessible Brønsted/Lewis acid, and good hydrophilicity. For the conversion of mono-, di-and poly-saccharides into 5-HMF, SP-MS exhibited remarkable activity. Typically, an 81% yield of 5-HMF with a complete glucose conversion was achieved in a biphasic NaCl–H2O/methyl isobutyl ketone solvent system at 170 °C within 45 min, obviously better than other heterogeneous acid catalysts. According to the kinetic study, the Lewis acid sites over SP-MS decreased the apparent activation energy (85 kJ mol−1) of glucose isomerization, and then the abundant Brønsted acid sites boosted the 5-HMF yields. More attractively, the catalytic activity can be restored after at least four cycles. This work is anticipated to provide insights into designing efficient and robust SAPO catalysts for 5-HMF production.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Taotao Zhao,Chenyang Shen,Gui Liu,Jun Yao,Xianghao Wang,Huajie Tao,Yu He,Yuchi Liu,Zhewei Zhang,Feifei Mei,Xiangke Guo,Luming Peng,Yan Zhu,Xuefeng Guo,Nianhua Xue,Weiping Ding
We report here a high-performance catalyst ReMoS x @HSSZ-39 compounded with SAPO-34 for conversion of CO 2 to C 2-4 hydrocarbons, in which the ReMoS x clusters are responsible for highly efficient hydrogenation of CO 2 to methanol as the intermediate and then the surrounding zeolitic acid sites for further conversion of methanol to hydrocarbons. The investigation finds that uniform ReMoS x clusters can be reliably fabricated in zeolitic cages by co-introduction of rhenium and molybdenum species into the HSSZ-39 zeolite and followed by sulfidation, which constitutes an intimate bifunction catalyst through better cooperation of ReMoS x clusters and the zeolitic acid sites. Compared with MoS x @HSSZ-39, the introduction of rhenium significantly suppresses CO generation. By mixing some SAPO-34 zeolite, with increased density of protonic acid, more than 86 % C 2-4 hydrocarbons in organic products and only 21 % CO at 32.5 % of CO 2 conversion are obtained and the composite catalyst shows excellent stability with more than 95 % C 2-4 hydrocarbons in organic products, less than 30 % CO and above 26.6 % of CO 2 conversion after 1000 h on stream.
研究领域:
催化化学
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2016
·
IF 2.208
Jixing Liu,Fuhong Yu,Jian Liu,Lifeng Cui,Zhen Zhao,Yuechang Wei,Qianyao Sun
A series of meso-microporous Cu-SAPO-34 catalysts were successfully synthesized by a one-pot hydrothermal crystallization method, and these catalysts exhibited excellent NH 3 -SCR performance at low temperature. Their structure and physic chemical properties were characterized by means of X-ray diffraction patterns (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), N 2 sorption-desorption, nuclear magnetic resonance (NMR), Inductively Coupled Plasma-Atomic Emission spectrometer (ICP-AES), X-ray absorption spectroscopy (XPS), Temperature-programmed desorption of ammonia (NH 3 -TPD), Ultraviolet visible diffuse reflectance spectroscopy (UV-Vis DRS) and Temperature programmed reduction (TPR). The analysis results indicate that the high activities of Cu-SAPO-34 catalysts could be attributed to the enhancement of redox property, the formation of mesopores and the more acid sites. Furthermore, the kinetic results verify that the formation of mesopores remarkably reduces diffusion resistance and then improves the accessibility of reactants to catalytically active sites. The 1.0-Cu-SAPO-34 catalyst exhibited the high NO conversion (> 90%) among the wide activity temperature window in the range of 150–425°C.
研究领域:
催化化学
·
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
CATALYSIS TODAY
·
2018
·
IF 4.667
Xianghui Li,Yingnan Zhao,Huawang Zhao,Mengke Liu,Yuhan Ma,Xin Yong,Hong Chen,Yongdan Li
Two kinds of Cu-SAPO-34 catalysts, prepared with a one-pot technique using Cu- tetraethylenepentamine as co-template and an ion-exchange method, were hydrothermally treated at 750 °C for at least 16 h. The migration of Cu species during hydrothermal treatment and the corresponding effect on the selective catalytic reduction (SCR) of NO x were examined and characterized. A certain amount of CuO exists outside and inner the crystallites in the as prepared ion-exchanged sample, whereas copper is mainly atomically dispersed in the one-pot sample existing as isolated Cu 2+ . After hydrothermal treatment for 16 h, the amount of the inner nanosized CuO in the ion-exchanged sample reduced and the copper disperses to form more isolated Cu 2+ . However, surface CuO particles increase at the sacrifice of isolated Cu 2+ with extending the hydrothermal treatment to 24 h. Aggregation of Cu 2+ species also happens during the aging treatment over the one-pot prepared sample where the initial Cu is atomically dispersed as isolated Cu 2+ . The increase of the amount of the isolated Cu 2+ enhances the low-temperature (< 350 °C) performance. However, the increase of the amount of surface CuO particles in the aged samples promotes the nonselective NH 3 oxidation reaction in the high temperature range and results in the lowering of the SCR activity by limiting NH 3 supply.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Guangpeng Yang,Xuesen Du,Jingyu Ran,Xiangmin Wang,Yanrong Chen,Li Zhang,Vladislav Rac,Vesna Rakic,John Crittenden
SCR activity of Cu-SAPO-34 catalyst was reduced by alkali metal ions. The alkali metals ions (Li + , Na + and K + ) have shown irregular influences on Cu-SAPO-34. The order of poisoning strengths under 400 °C was found to be: Na + > K + > Li + , which is not consistent with the basicities of their corresponding metals. Experimental results and calculations showed that the alkali metal ions readily replace H + and Cu 2+ /Cu + ions. These exchanges result in the loss of Brønsted acid sites and migration of isolated Cu 2+ ions in Cu-SAPO-34, which decrease the NH 3 -SCR activity. Both the basicity and ion diameter will affect the exchanging behavior of an alkali ion. Na + and Li + ions will influence both H + and Cu 2+ /Cu + ions but K + ions only preferably replace the H + . We hypothesize that K + cannot enter into a small ring (6-membered ring) to replace a Cu 2+ /Cu + ion because of its large ion diameter. The displaced Cu 2+ /Cu + ions will transfer to adjacent unbonded Al site to form a CuAlO 2 species.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Inorganic Chemistry Frontiers
·
2024
·Vol. 11
·期 5
·1596-1606
·
IF 6.1
Dehua Wang,Minghui Mo,Man Xu,Zhijun Xia,Xuebin Zhao,Beibei Gao
Seed-assisted synthesis of nano-SAPOs usually requires a costly nano-sized seed, and the micron-sized seed used should be ball-milled or treated under reflux to broke them into nano-particles. In this study, nano-sized SAPO-34 was prepared using a micron-meter SAPO-34-M seed that was treated facilely with morpholine (MOR) within a Teflon-lined stainless steel autoclave to obtain a seed solution. As MOR was also the template for SAPO-34 synthesis, no extra template was added to the precursor gel. The effects of MOR treatment time on seed properties and the subsequent SAPO-34 fabrication were characterized via XRD, SEM, N2 adsorption–desorption, 29Si NMR and NH3-TPD techniques. The effect of the seed amount on the products was also investigated. There existed optimum seed treatment time and seed addition amount for synthesizing uniform nano-sized SAPO-34 with the characteristics of larger mesopore volume, lower Si contents and acid density and weaker acid strength than conventional SAPO-34. Moreover, heterologous seed-assisted syntheses of SAPO-34 were carried out, and it is found that micron-sized heterologous seeds (AFI, RHO, LEV and AFX) treated with MOR can also deliver nano-sized SAPO-34, although AFI and RHO share no common composite building units (CBUs) with CHA, suggesting that seed selection in this synthesis strategy is not confined to a specific topology. The obtained nano-sized SAPO-34 catalysts exhibited about a 2.7-fold prolonged lifetime and nearly 5% increased selectivity for ethylene and propylene compared to their conventional micron-sized counterparts in methanol-to-olefin (MTO) reactions.
研究领域:
材料科学
·
催化化学
·
能源化学
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2021
·
IF 3.498
Shichao Zhang,Wenbin Chen,Ling Yang,Tong Xie,Weike Li,Daoke Yu,Yiwen Fang
SAPO-34 molecular sieve is one of the main catalysts for DMTO reaction and shows excellent catalytic performance. In this work, a series of Ni-SAPO-34 molecular sieve with different crystal morphologies , such as cubic, melting angle cube , spherical, polygon cube, were synthesized using Ni-DETA as a structure-directing agent. We explored the influence of Ni-DETA structure-directing agent on the formation of crystal morphology, and found that the different morphology is related to the amount of Ni-DETA introduced, and also had an impact on the acidity of the Ni-SAPO-34 molecular sieve. The properties of these samples were characterized by SEM, XRD , EDS, UV–Vis, FT-IR, NH 3 -TPD and N 2 physicalsorption. The synthesized polygonal cubic Ni-SAPO-34 molecular sieve has lower strong acidity due to the introduction of a small amount of nickel, which is beneficial to reduce the production of carbon deposits and improve the catalytic reaction activity. Moreover, the multi-edge morphology and hierarchical porous structure are also advantageous to the catalytic reaction. The polygon cube Ni-SAPO-34 catalysts display the highest DTO catalytic performance, and the total selectivity of ethylene and propylene can reach 83.76%.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）