JOURNAL OF CATALYSIS
·
2020
·
IF 7.888
Lei Wang,Peng Yin,Le-Le Zhang,Shan-Cheng Shen,Shi-Long Xu,Ping Chen,Hai-Wei Liang
Synthesis of supported Pd-based bimetallic catalysts is of great importance in the heterogeneous catalysis field owing to their optimal geometric and electronic effects. Downsizing active metals to ultrasmall nanocluster (<2 nm), which is mandatory for maximizing the metal atom utilization, however remains as formidable synthesis challenges. Here, we present a general synthetic approach to sub-2 nm Pd-based bimetallic nanoclusters on porous nitrogen-doped carbon supports, in which the strong chemical interaction between metal and nitrogen largely suppresses the metal aggregation during the H 2 -reduction at 400–500 °C. Through the nitrogen-fixing strategy, we prepare 9 sub-2 nm Pd-based bimetallic nanocluster catalysts by conventional impregnation process. The prepared supported bimetallic Pd-Pb nanocluster catalyst exhibit a high turnover frequency of 1092 h −1 for the semihydrogenation of phenylacetylene under a mild condition (30 °C, 5 bar H 2 ), along with a high selectivity of >93% to styrene, demonstrating the alloying and small-size effects in the bimetallic nanocluster catalysts.
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2020
·Vol. 10
·期 3
·302
·
IF 3.52
Meng Guo,Zhen Wei,Jianming Yang,Zunyuan Xie,Weiqiang Zhang
In the palladium-catalyzed C−C coupling reaction, electron-rich phosphine ligands and a catalytic amount of catalyst loading are required in most cases. Herein, a bench-stable, easily modified and less toxic alkynone was utilized in palladium-catalyzed Sonogashira coupling to replace conventional phosphine ligands. With 1-(4-methoxyphenyl)-3-phenyl-2-yn-1-one (L2) as the ligand, catalyst loading was reduced to 5-10 ppm. In this newly developed catalytic system, a variety of (hetero)arene iodines and alkynes could be tolerated, resulting in good yields of the corresponding cross-coupling products.Keywords:α;β-alkynone;Pd-catalyzed C−C coupling;π-acidicity
✓ 已验证
DOI
高影响因子
Advanced Healthcare Materials
·
2021
·Vol. 10
·期 21
·2101199
·
IF 9.933
Haihui Wang,Yongfei Liu,Xiaohui Zhu,Chengyun Chen,Zhangcheng Fu,Min Wang,Danying Lin,Zhaowei Chen,Chunhua Lu,Huanghao Yang
Combinatorial CpG oligonucleotide (CPG) and chemotherapy drug represent a promising approach to reactivate immune system. However, these two agents possess different physicochemical properties, hindering the application of direct self-assembly of these two cargos into a single nanostructure. Here, a multistage cooperative nanodrug is developed by the direct self-assembly of cis-platinum (CDDP, Pt), l -arginine ( l -Arg, R), and CPG (defined as PtR/CPG) for antitumor chemoimmunotherapy. First, the CDDP can induce cell apoptosis. Meanwhile, CDDP also promotes the production of H 2 O 2 , catalyzing the conversion of l -Arg into nitric oxide (NO). The generated NO decreases the multidrug resistance of cells toward CDDP. Thus, the synergistic effects of CDDP and NO can trigger immunogenic cell death to produce tumor-associated antigens (TAAs). The TAAs and CPG will induce the maturation of dendritic cells (DCs) and enhance antigen presentation ability of DCs. In this way, the PtR/CPG can reverse the immunosuppressive microenvironment, sensitizing tumors to immune checkpoint inhibitors mediated by the programmed death-ligand 1 (PD-L1) antibody. Furthermore, the PtR/CPG combined with the PD-L1 antibody decreases the exhaustion and dysfunction of cytotoxic T lymphocytes to elicit durable systemic immune response. As a result, the prepared PtR/CPG nanodrug in combination with PD-L1 may be highly significant for cancer immunotherapy.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2021
·Vol. 31
·期 51
·2107181
·
IF 18.808
Wen Zhang,Xue Jiang,Zemeng Dong,Jing Wang,Ning Zhang,Jie Liu,Guang-Rui Xu,Lei Wang
Modulating the morphology and chemical composition is an efficient strategy to enhance the catalytic activity for water splitting, since it is still a great challenge to develop a bifunctional catalyst for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) over a wide pH range. Herein, Pd/NiFeO x nanosheets are synthesized with tightly arranged petal nanosheets and uniform mesoporous structure on nickel foam (NF). The porous 2D structure yields a larger surface area and exposes more active sites, facilitating water splitting at all pH values. The overpotential of Pd/NiFeO x nanosheets for OER is only 180, 169, and 310 mV in 1 m KOH, 0.5 m H 2 SO 4 , and 1 m phosphate-buffered saline (PBS) conditions at 10 mA cm −2 current density, as well as excellent HER activity with ultralow overpotential in a wide pH range. When using porous Pd/NiFeO x nanosheets as bifunctional catalysts for water splitting, it just required a cell voltage of 1.57 V to reach a current density of 20 mA cm −2 with nearly 100% faradic efficiency in alkaline conditions, which is much lower than that of benchmark Pt/CǁRuO 2 (1.76 V) couples, along with the improving stability benefiting from the good corrosion resistance of the inner NiFeO x nanosheets.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 59
·34581-34588
·
IF 3.049
Li Wang,Yue Zhang,Qingqing Ma,Zhiyong Pan,Baoning Zong
Organosilane-functionalized mesoporous silica SBA-15 was prepared by the co-condensation method and then applied as a support of Pd catalysts for hydrogenation of 2-alkyl-anthraquinone (AQ, alkyl = ethyl, tert-butyl and amyl). The as-prepared Pd catalysts were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, N2 adsorption–desorption, zeta potential, water contact angles measurement and transmission electron microscopy. By extending the pre-hydrolysis time of the silica source, the content of functional groups in the catalysts slightly increases. However, there is an initial increase in zeta potential and water contact angles up to a maximum at 2 h, followed by a decrease as the pre-hydrolysis time was further prolonged. The hydrophobicity created by organic functionalization has positive effects on AQ hydrogenation. The catalyst with the highest hydrophobicity exhibits the highest catalytic activity, with increments of 33.3%, 60.0% and 150.0% for hydrogenation of ethyl-, tert-butyl- and amyl-anthraquinone compared with the unfunctionalized one.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nature Biomedical Engineering
·
2019
·Vol. 3
·期 4
·306-317
·
IF 17.135
Yao Han,Lan Jiang,Li Chushu,Shi Hubing,Brosseau Jean-Philippe,Wang Huanbin,Lu Haojie,Fang Caiyun,Zhang Yao,Liang Lunxi,Zhou Xiaolin,Wang Chaojun,Xue Yu,Cui Yun,Xu Jie
Checkpoint blockade therapy targeting the programmed-death ligand 1 (PD-L1) and its receptor programmed cell death 1 promotes T-cell-mediated immunosurveillance against tumours, and has been associated with marked clinical benefit in cancer patients. Antibodies against PD-L1 function by blocking PD-L1 on the cell surface, but intracellular storage of PD-L1 and its active redistribution to the cell membrane can minimize the therapeutic benefits, which highlights the importance of targeting PD-L1 throughout the whole cell. Here, we show that PD-L1 is palmitoylated in its cytoplasmic domain, and that this lipid modification stabilizes PD-L1 by blocking its ubiquitination, consequently suppressing PD-L1 degradation by lysosomes. We identified palmitoyltransferase ZDHHC3 (DHHC3) as the main acyltransferase required for the palmitoylation of PD-L1, and show that the inhibition of PD-L1 palmitoylation via 2-bromopalmitate, or the silencing of DHHC3, activates antitumour immunity in vitro and in mice bearing MC38 tumour cells. We also designed a competitive inhibitor of PD-L1 palmitoylation that decreases PD-L1 expression in tumour cells to enhance T-cell immunity against the tumours. These findings suggest new strategies for overcoming PD-L1-mediated immune evasion in cancer.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2019
·
IF 0
Shuo Li,Jiawei Liu,Guilin Zhu,Heyou Han
Conformal deposition of Pt-dots arrays on polyhedral Pd nanocrystals can enhance Pt catalytic properties and reduce its loading. Herein, a simple method for the fabrication of Pd@Pt core–shell nanodot arrays (Pd@PtNAs) heterostructures via reducing H2PtCl6 and Na2PdCl4 by l-ascorbic acid in an aqueous solution with cetylpyridinium chloride and KBr is reported. The Pt nanodots arrays with a small size (about 3 nm in diameter) were dispersed on the surface of Pd decahedra. Such ultrasmall size Pt dots arrays can effectively increase the proportion of low-coordination Pt atoms. Compared with commercially available Pt/C catalysts, the Pd@PtNAs show obvious improvement in catalytic performance applied to oxygen reduction reaction. The mass activity (0.20 A/mgPt) of the obtained Pd@PtNAs with 36.9 wt % Pt shows 2.2 times relative to Pt/C catalyst (0.09 A/mgPt) for ORR. What’s more, the Pd@PtNAs with 36.9 wt % Pt exhibited highly stable property and mass activity with only 11% loss after 10 000 testing cycle.
✓ 已验证
产品关联
DOI
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2018
·
IF 2.829
Ting Zou,You Han,Xinxue Li,Wei Li,Jinli Zhang,Yan Fu
Controlled synthesis of noble metal nanocatalysts with desirable catalytic activities remains a great challenge. Inspired by electron-rich functional groups and supramolecular assembly properties of natural nucleotides, herein we propose a versatile approach to construct Pd nanocatalysts through employing seven nucleotides as both electron donors and stabilizers . The catalytic performance of nucleotide-Pd complexes are greatly associated with the chemical structures of nucleobases as well as the number of phosphate groups . Guanosine 5′-triphosphate-Pd complexes possess high activities in the hydrogenation reduction of 4-nitrophenol assisted by NaBH 4 , with the relative rate constant of 7770 min −1 mM −1 at 25 °C. Pd(II)-coordinated nucleotides are also promising in NaBH 4 -mediated degradation of organic dyes. This work demonstrates a green and facile process to construct Pd nanocatalysts containing abundant active sites under the assistance by natural nucleotides.
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2018
·
IF 9.89
Junbo Zhang,Weiwei Xu,Lai Xu,Qi Shao,Xiaoqing Huang
Although considerable studies on pursuing high-performance Pd-based catalysts for the semihydrogenation of alkynes have been carried out, the creation of catalyst with high activity, selectivity and stability simultaneously toward semihydrogenation reactions remains a significant challenge. Herein, for the first time we report a facile synthetic strategy to realize the intermetallic Pd–Pb nanocubes with different concave degree by selectively utilizing small molecules. These obtained Pd–Pb nanocrystals exhibit high activity in the semihydrogenation of alkynes, where their performances are highly shape- and composition-dependent with Pd–Pb concave nanocubes showing the optimized alkene selectivity of 94.6% and activity of 179.2 h–1, much higher than those of 10% Pd/C. Detailed X-ray photoelectron spectroscopy results show that the higher ratio of metallic Pd results in the higher activity for semihydrogenation of phenylacetylene and the higher ratio of Pb2+ and Pb/Pd contribute to higher styrene selectivity. The density functional theory calculations further reveal that the favorable adsorption energy of phenylacetylene and desirable desorption energy of styrene on the Pd3Pb surface are critical for the phenylacetylene semihydrogenation with excellent activity and high selectivity. Furthermore, the Pd–Pb concave nanocube can endure at least five cycles with very limited conversion and selectivity decays, representing an efficient Pd-based catalyst for selective hydrogenation and beyond.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2014
·Vol. 2
·期 12
·4384-4390
·
IF 0
Jing-Jing Lv,Jie-Ning Zheng,Shan-Shan Li,Li-Li Chen,Ai-Jun Wang,Jiu-Ju Feng
In this report, well-dispersed porous Pt–Pd nanodendrites (Pt–Pd NDs) were synthesized at high yield by a simple, one-pot, wet chemical method without using any seed, template, or toxic organic solvent. Poly(vinylpyrrolidone) (PVP) and urea were employed as the co-stabilizing and co-structure-directing agents. It was found that the reaction temperature, the amount of PVP and urea, the Pt/Pd molar ratio, and the pH value of the reaction media greatly affected the size and shape of the Pt–Pd product. The as-prepared Pt–Pd nanocrystals had a larger active surface area, superior catalytic activity, and better stability for the electrooxidation of methanol and ethylene glycol (EG), compared with the commercial Pt-black and Pd-black catalysts.
✓ 已验证
产品关联
DOI
MATERIALS RESEARCH BULLETIN
·
2016
·
IF 2.435
Xixia Zhao,Guijuan Wei,Junxue Liu,Zhaojie Wang,Changhua An,Jun Zhang
TiO 2 /TiOF 2 heterostructured nanocomposites has been synthesized through a solvothermal method and characterized by X-ray diffraction, scanning electronic microscopy, transmission electronic microscopy, nitrogen adsorption–desorption isotherms, UV–vis and photo-luminescent spectroscopy. It was found that, compared with single TiOF 2 or TiO 2 , the as-prepared TiO 2 /TiOF 2 nanocomposites exhibited superior photoactivity towards the degradation of organic pollutants, i.e . rhodamine B and solar hydrogen evolution. The results are in accordance with the prohibition of photogenerated electrons and holes recombination in these two samples under light illumination. The photocatalytic activity can be further boosted by introducing Pd nanoparticles onto the surfaces of TiO 2 /TiOF 2 through a simple deposition method without using any stabilizers, which is probably attributed to the enhanced visible-light absorption as well as the facilitated charge-carrier separation after the introduction of Pd nanoparticles. The synergistic effect between TiOF 2 and TiO 2 was discussed and was responsible for the enhancement of their activity in comparison with single counterpart.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 26
·21337-21344
·
IF 3.289
Hong Jiang,Songlin Xue,Yefei Liu,Rizhi Chen,Weihong Xing
The Pd@ZIF-L catalysts with uniform crosshair-star shape and a size of about 20 μm were fabricated by an assembly method that enables the crystallization of ZIF-L in water with the presence of polyvinylpyrrolidone (PVP)-stabilized Pd nanoparticles (NPs). The physical and catalytic properties of the Pd@ZIF-L catalysts are greatly affected by the molar ratios of 2-methylimidazole (2-MeIM)/Zn2+ and PVP/Zn2+. Their catalytic activities were evaluated by the catalytic reduction of p-nitrophenol to p-aminophenol. The results indicate that a lower molar ratio of 2-MeIM/Zn2+ is beneficial for the increase of Pd loading and p-nitrophenol conversion, but a suitable molar ratio (≥20) of 2-MeIM/Zn2+ is helpful to the crystallization of ZIF-L and the encapsulation of the Pd NPs within the ZIF-L framework. The Pd@ZIF-L catalyst synthesized at a lower PVP/Zn2+ molar ratio has higher Pd loading and p-nitrophenol conversion due to the easy adsorption of PVP–Pd NPs onto the ZIF-L surfaces. This work would aid the development of high-performance Pd@ZIF-L catalysts.
✓ 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）