CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Qianqian Li,Hairong Yue,Changjun Liu,Kui Ma,Shan Zhong,Bin Liang,Siyang Tang
Transformation from photocatalytic oxidative dehydrogenation of ethane (PODHE) to photocatalytic dehydrogenation of ethane (PDHE) is an attractive process. A series of Pd/TiO 2 photocatalysts with different Pd loading amount were synthesized by photochemical deposition. And the Pd particle sizes varied from 1 nm to 4 nm. PDHE happened instead of POHDE over Pd particles smaller than 3 nm. The best PDHE performance (H 2 , 799.4; C 2 H 4 , 614.9, in micromoles per gram of catalyst) was obtained over 0.5 wt.% Pd/TiO 2 catalyst. And it was 3 times of it of PODHE over 1 wt.% Pd/TiO 2 . Reducing the Pd particle size of Pd/TiO 2 would increase Pd 0 /Pd 2+ and lower the valence band and conductive band of Pd/TiO 2 , which affect the catalytic behaviors. Detailed formation of products was investigated in this work.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2025
·
IF 2.5
Meng Li,Diangen Zhou,Hualiang An,Shanshan Dong,Xinqiang Zhao,Yanji Wang
2-Ethylhexanal (2EH) is an important intermediate for the production of 2-ethyhexanoic acid (2-ETA), and studying the direct synthesis of 2EH through heterogeneous catalysis of n-butanal aldol condensation-selective hydrogenation reaction integration is of great significance for the industrial production of 2-ETA. Herein, a series of Pd/TiO2 catalysts were prepared and characterized by XRD, CO pulse adsorption, TEM, CO2/NH3-TPD and H2-TPR. Their catalytic performance for direct synthesis of 2EH from n-butanal was investigated in stainless steel autoclave first. The results showed that the Pd/TiO2 prepared by the excessive impregnation method, loaded with 0.5 wt.% of Pd, and reduced at 400 ℃ showed excellent catalytic performance: 95.4% conversion of n-butanal and up to 99.9% selectivity of 2EH. The particle size of Pd, the base strength and the amount of acid/base of the catalyst are the main factors affecting its catalytic performance. The smaller the particle size of Pd, the greater the base strength and the larger the amount of acid/base of the catalyst, the better its catalytic performance. Then the integrated reaction mechanism was established based on the results of characterization and FT-IR of online sampling. Furtherly, the continuity of the reaction process was achieved on fixed-bed reactor. Under the reaction conditions of a liquid hourly space velocity (LHSV) of 7.2 h-1, a reaction temperature of 190 °C and a H2 pressure of 3.2 MPa, the conversion of n-butanal and the selectivity of 2EH were 91.2% and 89.8%, respectively. During the continuous operation for 300 h under optimal conditions, the conversion of n-butanal decreased slightly first and then stabilized, while the selectivity of the target product 2EH remained basically unchanged.
研究领域:
催化化学
·
工业化学
✓ 已验证
产品关联
DOI
高影响因子
Materials Chemistry Frontiers
·
2020
·Vol. 4
·期 6
·1671-1678
·
IF 6.788
Ping She,Jun-sheng Qin,Heng Rao,Buyuan Guan,Jihong Yu
Efficient charge separation and light harvesting of photocatalysts (e.g., TiO2) are the key issues to be considered in the design of solar-energy conversion systems. In particular, the charge separation of noble metal-decorated TiO2 materials could be greatly improved via decreasing the size of noble metal particles (NPs). Furthermore, designing specific morphologies such as hollow structures can improve light harvesting ability. Herein, a hybrid hollow TiO2 with spatially separated bimetals (Pd@TiO2@Au) was prepared, which demonstrated enhanced charge separation. By choosing zeolite as the sacrificial substrate, ultrasmall Pd NPs and Au NPs were decorated in the inner and outer shells of hollow TiO2, respectively. The separated bimetals could pull the photoexcited electrons away from the surface of TiO2 for more efficient charge separation. The as-prepared Pd@TiO2@Au catalyst exhibited a superior photocatalytic H2 evolution rate up to 272.3 μmol h−1, which was higher than most of the TiO2-based photocatalysts.
研究领域:
材料科学
·
光催化
·
太阳能转换
✓ 已验证
DOI
高影响因子
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2021
·
IF 3.935
Xinying He,Han Cao,Xia Li,Yan Li,Yunqiu Yu
Lysophosphatidylcholine (LPC) was commonly known as a class of significant differential metabolites of high relevance with many diseases including psoriasis, of which the accurate determination is of great importance to diagnosis or prediction to many diseases. However, it is challenging and complicated because of the enormous biological sample complexity and impurities interference. In this study, we synthesized a magnetic nanocomposite MG@PD@TiO 2 and took advantage of the interactions of Lewis acid−base between the phosphate groups in LPCs and Ti ions on MG@PD@TiO 2 nanomaterials for selective separation and enrichment of LPCs from complex biological matrix. The solid-phase extraction sample pretreatment process by means of MG@PD@TiO 2 nanomaterials coupled with LC–MS/MS method was then applied to actual determination of six typical LPCs (LPC 10:0, 14:0, 16:0, 18:0, 18:1, 22:0) in human plasma. The extraction conditions were scientifically optimized by single-factor test (adsorbent amount, adsorption and desorption time, elution solvent type, eluant volume). Under the optimal conditions, the detection limits (LOD, S/N = 3) and quantification limits (LOQ, S/N = 10) were 1 and 5 ng/mL for LPC 10:0 and LPC 14:0, 0.02 and 0.1 ng/mL for LPC 16:0 and LPC 18:1, 0.05 and 0.2 ng/mL LPC 18:0 and LPC 22:0, respectively. The intra- and inter-day precisions were 3.82–12.60 % (n = 6) and 3.29–13.50 % (n = 6) respectively, the recoveries were in the range of 91.92–113.69 % and the stability of the analytes in the matrix performed well with RSDs≤15.51 %. Finally, the developed method was successfully applied to the accurate determination of six LPCs biomarkers of plasma in patients with psoriasis (n = 10) and control groups (n = 10).
研究领域:
分析化学
·
医学
·
生物标志物研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）