RSC Advances
·
2017
·Vol. 7
·期 12
·7140-7149
·
IF 3.108
Yuchao Xu,Zongzhang Liu,Zheng Han,Minhua Zhang
ZnO promoted ZrO2–SiO2 catalysts synthesized by a sol–gel method were investigated in the two-step ethanol transforming to 1,3-butadiene process. The influence of promoters and the preparation method of the catalysts on the catalytic performance were studied in detail and the reaction conditions were optimized. The as-prepared catalysts were characterized by BET, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Resonance (FT-IR), X-ray photoelectron spectroscopy (XPS), FT-IR spectroscopy of adsorbed pyridine (Py-IR) and temperature-programmed desorption of NH3 (NH3-TPD). ZnO added ZrO2–SiO2 catalysts show the best catalytic activity and the catalysts prepared by the hybrid sol–gel method were superior to those prepared by the sol–gel coupled with impregnation method. The addition of promoters in the ZrO2–SiO2 system decreased the total acidity and lowered the selectivity to dehydration products. The best performance with ethanol/acetaldehyde conversion of 40.7% and 1,3-butadiene selectivity of 83.3% was reached at 310 °C, ethanol/acetaldehyde mole ratio of 3.5 and WHSV of 1.4 h−1 using a 0.5 wt% ZnO doped ZrO2–SiO2 catalyst.
研究领域:
催化化学
·
材料科学
·
能源化工
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 126
·103982-103988
·
IF 3.84
Zheng Han,Xiang Li,Minhua Zhang,Zongzhang Liu,Meixiang Gao
A series of ZrO2–SiO2 catalysts synthesized by sol–gel method were investigated for the 1,3-butadiene formation from bioethanol and acetaldehyde. The influence of ZrO2 content and reaction conditions on catalytic performance were studied. The catalysts were characterized by N2 adsorption–desorption analysis, temperature-programmed desorption of NH3 (NH3-TPD), IR spectroscopy of adsorbed pyridine (Py-IR), Fourier Transform Infrared Resonance (FTIR), X-ray diffraction (XRD) and Transmission Electron Microscope (TEM). These characterization results indicated that suitable intensity of acid sites, especially Lewis acid, are very crucial to obtain an active catalyst. The catalysts showed significantly higher selectivity for C4 chemicals, and 2 wt% ZrO2 content reached the highest selectivity to BD (69.7%), at space velocity (WHSV) of 1.8 h−1.
研究领域:
催化化学
·
可再生资源转化
·
材料科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 59
·34069-34077
·
IF 2.936
Minhua Zhang,Xuechao Tan,Tong Zhang,Zheng Han,Haoxi Jiang
A deactivation study on the ethanol/acetaldehyde conversion to 1,3-butadiene over a ZnO promoted ZrO2–SiO2 catalyst prepared by a sol–gel method was performed. The samples were characterized by N2 adsorption–desorption isotherms, scanning electron microscopy (SEM), NH3 temperature programmed desorption (NH3-TPD), X-ray powder diffraction characterization (XRD), thermogravimetric analyses (TGA), Fourier transform infrared resonance (FT-IR), 13C magic-angle spinning nuclear magnetic resonance (13C NMR) and X-ray photoelectron spectroscopy (XPS). The pore structure characteristics and surface acidity of Zn0.5–Zr–Si catalysts were largely decreased with time-on-stream and no crystal structure was formed in the used catalyst, indicating that the deactivation was caused by carbon deposition. Two main types of carbon deposition were formed, namely low-temperature carbon deposition with the oxidation temperature of around 400 °C and high-temperature carbon deposition with the oxidation temperature of 526 °C. The carbon species were mainly composed of graphitized carbon, amorphous carbon, carbon in C–O bonds and carbonyls. The deactivated catalyst could be regenerated by a simple oxidation process in air. Adding a certain amount of water into the feed had a positive effect on reducing the carbon deposition.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED ENERGY
·
2019
·
IF 8.426
Zain Ali Saleh Bairq,Hongxia Gao,Yufei Huang,Haiyan Zhang,Zhiwu Liang
A significant impediment to the widespread adoption of amine-based post-combustion technique for CO 2 capture from flue gas is the huge energy demand for amine solvent regeneration. In this study, five novel bifunctional heterogeneous catalysts e.g., SO 4 2− /ZrO 2 /SiO 2 with different molar ratios of zirconia and SO 4 2− /ZrO 2 as a parent catalyst were synthesized and applied to evaluate their effectiveness in enhancing the CO 2 desorption and solvent regeneration of 5M monoethanolamine solution with CO 2 loading of 0.5 ± 0.01 mol CO 2 /mol monoethanolamine at 97 °C. The catalysts were characterized by Fourier transform-infrared spectrometry, pyridine-infrared spectroscopy, X-ray diffraction, N 2 -adsorption-desorption, and ammonia-temperature programmed desorption. The results demonstrated that these catalysts can significantly reduce the heat duty for CO 2 desorption by 36.48% compared to without catalyst and enhance desorption rate by 35.1%. The results also showed that SO 4 2− /ZrO 2 /SiO 2 15% presented the highest efficiency compared to the other SO 4 2− /ZrO 2 /SiO 2 ratios and the super solid acid catalyst SO 4 2− /ZrO 2 . Additionally, to investigate if the catalysts induce any unfavorable effects on the amine, the absorption of CO 2 by regenerated amine solvent was studied. Finally, a reaction mechanism for the amine solvent regeneration with the synthesized catalyst e.g., SO 4 2− /ZrO 2 /SiO 2 was suggested.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2022
·
IF 5.723
Boyong Ye,Ruru Zhou,Caili Wang,Zixuan Wang,Zixin Zhong,Zhaoyin Hou
Polylactic acid (PLA) is popularly used to replace some petroleum-based polymers due to its biodegradability. However, biodegradation of waste PLA requires specific bacteria, stringent conditions and long time. Catalytic recycling of waste PLA to valuable added products rather than composting is a sustainable green routine. In this work, catalytic alcoholysis of waste PLA to methyl lactate (MLA) was carried out over a SiO 2 @UiO-66 derived solid acid (SO 2– 4 /ZrO 2 /SiO 2 ). Characterizations indicated that SO 2– 4 /ZrO 2 /SiO 2 processed large surface area and homogenously dispersed acid sites, and it exhibited excellent performance for the alcoholysis of waste PLA under mild conditions. At 140 o C, the yield of MLA is 92.7% within 5 h, and SO 2– 4 /ZrO 2 /SiO 2 could be recycled at least five times without obvious loss of activity. The specific yield of MLA over SO 2– 4 /ZrO 2 /SiO 2 reached 2678 mg-MLA/g-cat/h, which was higher than that of H 3 PW 12 O 40 , Amberlyst-45, H β , HZSM-5 and α -ZrP. At the same time, SO 2– 4 /ZrO 2 /SiO 2 was also capable of the alcoholysis of waste PLA-based products. A possible pathway of PLA alcoholysis over SO 2– 4 /ZrO 2 /SiO 2 catalyst was proposed.
研究领域:
化学工程
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2019
·
IF 4.191
Gaofeng Chen,Tingzhou Lei,Zhiwei Wang,Shijie Liu,Xiaofeng He,Qian Guan,Xiaofei Xin,Haiyan Xu
A mesoporous composite CoCuK/ZrO 2 -SiO 2 catalyst with high activity and long life was prepared by vacuum impregnation and multisolvent self-assembly. The catalytic activity of the mesoporous catalyst was investigated for the synthesis of ethanol and higher alcohols from biomass syngas from wheat straw. The catalyst was characterized by small-angle X-ray diffraction, power XRD, N 2 adsorption and desorption experiments (BET), and transmission electron microscopy (TEM). The effects on the reaction activity and products from the addition of alkali metal promoter K, the modification of ZrO 2 and different copper/cobalt compositions were analyzed. The life of the catalyst was determined using a pressurized fixed-bed reactor. The results show that the catalyst possesses the high CO hydrogenation activity, high C 2+ OH selectivity and high life expectancy needed to meet industrial applications.
研究领域:
催化化学
·
可再生能源
·
材料科学
✓ 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）