Catalysts
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2022
·Vol. 12
·期 7
·685
·
IF 4.501
Hao Dong,Cheng-Hua Xu,Fang-Lu Yang,Lei Du,Chen-Long Liu,Wen-Jing Chen,Lin Wang
Ca–Zr–Sn composite oxides catalysts for 1,4-butanediol (BDO) selective dehydration to 3-butene-1-ol (BTO) are synthesized by impregnation and co-precipitation in the present work. The results show that Ca–Zr–Sn catalysts prepared from co-precipitation by using NaOH-Na2CO3mixing alkali solution as precipitant exhibit an excellent catalytic property for BDO dehydration to BTO. For instance, Ca–Zr–Sn oxide with Ca/Zr and Sn/Zr molar ratio of 0.68 and 0.28 calcined at 650 °C gives a BDO conversion and BTO selectivity of about 97% and 82%, respectively, and exhibits no deactivation during 1000 h scale-up experimental testing. X-ray diffraction results indicate that catalytic active centers for BDO dehydration to BTO are from Ca0.15Zr0.85O crystal phase. NH3- and CO2-temperature programmed desorption prove that the surface of obtained catalysts can provide a large amount of acid and base sites simultaneously. FT-IR spectra of pyridine-adsorbed samples show that acid sites on the surface of Ca–Zr–Sn oxide catalyst mainly exist in a state of Lewis acid, which activates terminal -OH groups of BDO molecule through complexing. The activated -OH interacts with β-H activated on base sites O2−anions relative to Ca species, thereby the CH2=CH- bonds are produced through dehydration to form BTO.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
DOI
高影响因子
Arabian Journal of Chemistry
·
2022
·
IF 6.212
Min Liang,Huixia Zhao,Suyi Dai,Chang Yu,Haijun Cheng,Weiguang Li,Fang Lai,Li Ma,Xiongmin Liu
1,3-Butadiene is the simplest conjugated diene, which is widely used in polymer materials, organic synthesis, and other fields. The investigation of its thermal stability and oxidation characteristics is necessary for production, transportation, and use safety. The pressure and temperature behavior of the autoxidation reaction of 1,3-butadiene with oxygen were determined using a custom-designed mini closed pressure vessel test (MCPVT). The effects of free radical initiators CHP and AIBN on the oxidation reaction were investigated. The thermal decomposition characteristics of oxidation products were measured by differential scanning calorimetry (DSC), and its hazards were discussed. The results showed that the oxidation reaction of 1,3-butadiene was easy to occur. Moreover, the activation energies of autoxidation, CHP-initiated oxidation, and AIBN-initiated oxidation reaction were 20.85 kJ·mol −1 , 33.30 kJ·mol −1 , and 56.27 kJ·mol −1 , respectively. In addition, the oxidation products were analyzed by headspace sampler-gas chromatography-mass spectrometry (HS-GC–MS), GC–MS, and iodometry. Some of 1,3-butadiene oxidation products under three conditions are the same, for example, 3-butene-1,2-diol, 4-vinylcyclohexene, 2(5H)-furanone, 2-propen-1-ol, and 2,6-cyclooctadien-1-ol. According to the reaction products, the oxidation reaction pathway of 1,3-butadiene was described. The research results are significant for avoiding fire and explosion accidents in the production, transportation, and application of 1,3-butadiene.
研究领域:
化学工程
·
有机化学
·
热分析
·
安全科学
✓ 已验证
DOI
高影响因子
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