JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2024
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IF 9.4
Lang Wu,Jianxin Cao,Chengbing Fu,Zheng Chen,Chaochuang Yin,Qian Lin,Hongyan Pan,Keliang Wang
Direct synthesis of hydrogen peroxide (DSHP) from oxygen (O 2 ) and hydrogen (H 2 ) offers a promising alternative to anthraquinone oxidation for hydrogen peroxide (H 2 O 2 ) production, yet challenges remain in achieving high selectivity and productivity. In this study, palladium octahedral nanoparticles (Pd ONPs) exposing Pd(111) facets were first synthesized, followed by the introduction of lead (Pb) atoms onto these facets to construct Pb-Pd(111) surface alloy structures (Pd@Pd-Pbx ONPs) for efficient DSHP. Characterization results indicated that the introduction of Pb atoms increased the electron density of Pd atoms and significantly reduced the number of low-coordinated Pd atoms. Density functional theory (DFT) calculations confirmed that the high electron density in Pd atoms downshifted their d-band center, thereby enhancing the adsorbed O 2 (O 2 *) and hydroperoxyl (OOH*) hydrogenation and promoting the adsorbed H 2 O 2 (HOOH*) desorption from Pd active sites, which was a key step in the formation of H 2 O 2 . Furthermore, the different coordination environments and electronic properties of Pd atoms that were close to Pb as opposed to those that were farther away produced a unique tilted adsorption configuration for O 2 *, OOH*, and HOOH* on the Pd-Pb(111) surface, effectively inhibiting O O bond dissociation. As a result, the TiO 2 -loaded Pd@Pd-Pb 4 ONPs (Pd@Pd-Pb 4 /TiO 2 ) catalyst achieved an H 2 O 2 selectivity of 80.6 % and a productivity of 6258.7 mmol g Pd -1 h −1 in the DSHP. This study underscores the impact of Pd catalyst surface modification on DSHP performance and provides valuable insights into the structure-performance relationship in bimetallic catalysts.
研究领域:
催化化学
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材料科学
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理论计算
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产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Amir Said,Caiyun Liu,Chang Gao,Dexin Wang,Huihui Niu,Yanshu Liu,Guo Wang,Chen-Ho Tung,Yifeng Wang
The CO2 cycloaddition to epoxides is an efficient method for CO2 capture and storage, important not only for reducing greenhouse gas emission but also for producing cyclic carbonates, which are valuable industrial materials. In this study, we report a novel high-nuclearity titanium oxide cluster (TOC) inlayed with main-group element Pb2+, H2Ti16Pb9O24(SA)18(DMF)10(OH2)2 (denoted as 1; SA = salicylate; DMF = N,N-dimethylformamide), which has the property of visible-light absorption and has shown high catalytic activities for cycloadditions of CO2 under visible-light irradiation. The cluster was synthesized in a high yield in a facial solvothermal process. Its structure and electronic structure were characterized by single-crystal X-ray diffraction, density functional theory calculations, and complementary techniques. The cycloaddition reactions were performed under solvent-free conditions. While the catalytic activity due to the Lewis acidity was moderate, visible-light irradiation further folded the reaction rates. The turnover number reached 3400 with a turnover frequency of 120 h–1. Mechanism studies indicated a synergistic effect of the Lewis acidity and photogenerated charge carriers. The performance of 1 in reversible I2 uptake was also investigated. This study demonstrates the high potential of heterometal-decorated TOCs in the cost-effective and efficient CO2 cycloaddition reaction under mild conditions.
研究领域:
材料科学
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催化化学
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环境科学
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产品关联
DOI
PubMed
高影响因子
MRS Communications
·
2022
·Vol. 12
·期 4
·460-464
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IF 2.935
Xu Min,Chen Botong,Wang Qi,Zhang Yuan,Wang Yuhao,Duhm Steffen,Liu Lijia
Methylammonium lead halide perovskite (MAPbX 3 ) has been a great candidate for photovoltaic applications. However, dissociation of the methylammonium unit has been observed, producing a CH 3 – group binding to MAPbX 3 and a free NH 3 molecule. To date, there is no clear evidence on the specific binding site of CH 3 –. In this study, MAPbBr 3 thin films are prepared with deliberately added trimethyl lead bromide, (CH 3 ) 3 PbBr. X-ray photoelectron spectroscopy is applied to comparatively investigate the electronic structure of MAPbBr 3 films with and without (CH 3 ) 3 PbBr modification. CH 3 -Pb species are identified, confirming that Pb is a binding site for CH 3 produced upon MA dissociation. Graphical abstract
研究领域:
材料科学
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物理化学
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产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2019
·Vol. 21
·期 15
·4143-4151
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IF 9.405
Shanjun Mao,Bowen Zhao,Zhe Wang,Yutong Gong,Guofeng Lü,Xiao Ma,Lili Yu,Yong Wang
Semi-hydrogenation of alkynols to alkenols with Pd-based catalysts is of great significance in fine chemical industries. Industrial Lindlar catalysts, employing Pb to modify the Pd nanoparticles for higher selectivity toward alkenols, however, generally suffer from both a severe activity decrease and environment pollution caused by using heavy metal Pb and additives. Therefore, how to overcome the selectivity–activity paradox remains a great challenge in industry. Here, we report a controllable strategy for the synthesis of semi-hydrogenation catalysts, which successfully improves the catalytic performance through selectively poisoning the edge and corner sites of Pd nanoparticles. When the integrity of the crystal face is reserved, both higher activity (∼1340 h−1) and selectivity (∼95% at 99% conversion) are achieved in the semi-hydrogenation of 2-methyl-3-butyn-2-ol (MBY) in ethanol, an industrially important intermediate product for the synthesis of vitamin E, without adding any toxic additives. What's more, the yield could exceed 98% at 99% conversion under no solvent and organic adsorbate conditions, which had never been achieved before. This work provides a different perspective to design and develop high performance catalysts for semi-hydrogenation of alkenols or even substituted alkynes.
研究领域:
催化
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化学工程
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精细化工
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）