BIOMATERIALS
·
2023
·
IF 14
Ziwen Qiu,Zhenming Lu,Jiaqi Huang,Yingtao Zhong,Ni Yan,Renjiang Kong,Hong Cheng
Tumor cells overexpress programmed cell death ligand 1 (PD-L1) to impede immune responses and escape immune elimination. Development of effective combination regimens to sensitize immunotherapy is promising but always challenging. Herein, a self-reinforced photodynamic immunostimulator (designated as PCS) is constructed for metastatic breast cancer treatment through simultaneous downregulation and blockade of PD-L1. Specifically, PCS is prepared by encapsulating signal transducer and activator of transcription 3 (STAT3) inhibitor (Stattic) into photosensitizer (protoporphyrin IX) modified PD-L1 blockade peptide (CVRARTR) through drug self-assembly. PCS can facilitate the targeted drug accumulation in PD-L1 overexpressed breast cancer cells to block PD-L1 and inhibit the phosphorylation of STAT3 to downregulate PD-L1. Moreover, PCS increases intracellular oxidative stress to show a robust anti-proliferation effect through photodynamic therapy (PDT), which also triggers an immunogenic cell death (ICD) to expose the immunostimulatory signals. Consequently, the efficient PD-L1 inhibition and robust PDT of PCS synergistically suppress the malignant growth of breast cancer, and concurrently activate the systemic anti-tumor immunity for metastatic inhibition with no obvious side effects. Such a photodynamic immunostimulator may provide an effective combination regimen for therapies activated immunotherapy against metastatic breast cancer.
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DOI
PubMed
高影响因子
Nanoscale
·
2023
·Vol. 16
·期 1
·335-342
·
IF 6.7
Yinglei Liu,Chicheng Ma,Jiye Zhang,Huiying Zhou,Gaowu Qin,Song Li
The electronic interaction between a metal and a support modulates the electronic structures of supported metals and plays an important role in manipulating their catalytic performance. However, this interaction is mainly realized in heterogeneous catalysts composed of reducible oxides. Herein, we demonstrate the electronic interaction between γ-Al2O3 and η-Al2O3 with varying acid–base properties and supported Pd nanoparticles (NPs) of 2 nm in size. The strength and number of acid–base sites on the supports and catalysts were systemically characterized by FT-IR spectroscopy and TPD. The supported Pd NPs exhibit electron-rich surface properties by receiving electrons from the electron-donating basic sites on γ-Al2O3, which are beneficial for catalyzing the hydrogenation of nitrobenzene. In contrast, Pd NPs loaded on η-Al2O3 are electron-deficient because of the rich electron-withdrawing acid sites of η-Al2O3. As a result, Pd/η-Al2O3 exhibits higher catalytic activity in phenylacetylene hydrogenation than Pd/γ-Al2O3. Our results suggest a promising route for designing high-performance catalysts by adjusting the acid–base properties of Al2O3 supports to maneuver the electronic structures of metals.
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PubMed
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2017
·
IF 4.217
Yunhua Li,Xing Zhang,Hua Zhang,Binghui Chen,Kevin J. Smith
This work compares the stability of Ni 2 P/SiO 2 , Pd/SiO 2 and Pd-Ni 2 P/SiO 2 catalysts during phenol hydrodeoxygenation (HDO) in the presence of H 2 O. The Pd-Ni 2 P/SiO 2 catalyst (PNP) was prepared by an in-situ reduction method in which PdCl 2 is added directly to unpassivated Ni 2 P/SiO 2 . A series of physicochemical characterizations, such as X-Ray diffraction, transmission electron microscopy, thermogravimetry, temperature programmed reduction and X-ray photoelectron spectroscopy were used. The results showed that the PNP catalyst has the highest stability among these catalyts. Phenol conversion and cyclohexane selectivity vary from 100.0% to 93.0% and from 94.2% to 83.1%, respectively with 0.1 g catalyst at 2 MPa and 493 K in four reaction cycles. Enhanced stabiltiy is attributed to Pd highly dispersed and strongly interacting with Ni 2 P on the PNP catalyst, resulting in negligible aggregation and loss of metal as well as very low carbon formation over the PNP catalyst. In contrast, the deactivation of Pd/SiO 2 results from aggregation and loss of Pd, while that of Ni 2 P/SiO 2 is due to the loss of phosphorus, phosphide oxidation and carbon deposition in the presence of H 2 O.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Cong Wu,Qinglong Liu,Yu Zhan,Wei Tan,Xiaoqian Wei,Qing Tong,Haiqin Wan,Lin Dong
Indoor volatile organic compounds (VOCs), represented by toluene, can pose a serious threat to human health. In this work, a series of Pd/TiO 2 catalysts with different surface structures ( i.e. , dispersion/valence of Pd species, surface Ti 3+ /oxygen defect concentration and Pd-TiO 2 interactions, etc. ) was constructed by various methods. It was found that the Pd/TiO 2 catalyst prepared by one-step reduction of NaBH 4 method (Pd/TiO 2 -N) with metallic Pd particles possessed more surface Ti 3+ /oxygen defects and stronger Pd-TiO 2 interaction than Pd/TiO 2 catalysts prepared by ethylene glycol reduction loading method (Pd/TiO 2 -E) and incipient wetness impregnation method (Pd/TiO 2 -I). Further photochemical characterizations and reaction mechanism study revealed that the relatively higher concentration of Pd 0 species on Pd particles, stronger Pd-TiO 2 interaction, and more surface Ti 3+ /oxygen defects on Pd/TiO 2 -N could facilitate the generation of more reactive oxygen species (ROS) under light irradiation. The partial oxidation of toluene to benzyl alcohol/benzaldehyde/benzoic acid and the subsequent ring-opening process were found to be highly determined by the valence states of Pd particles and the concentration of surface Ti 3+ /oxygen defects. This work provides instructive insights into the construction of highly efficient Pd/TiO 2 catalysts for the removal of indoor VOCs.
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高影响因子
APL Materials
·
2023
·Vol. 11
·期 10
·
IF 6.1
Li Xia,Deng Min,Cao Tingting,Ma Jun,Geng Shuo,Ren Yuan,Yao Mengqin,Liu Fei,Dong Yonggang
Formic acid (FA, HCOOH), as a liquid chemical hydrogen storage carrier with low cost, high hydrogen content, and convenient storage and transportation, has attracted extensive attention. Pd-based catalysts for hydrogen production from FA are easy to aggregate and deactivate in the reaction process, which hinders the further development of FA as a hydrogen storage carrier. Therefore, the exploitation of carriers with simple preparation methods and excellent performance can effectively improve the catalytic activity of Pd-based catalysts. Porous carbon and SiO 2 have been widely used for their unique structural properties, and the preparation of composite carriers by combining the advantages of both is a current research hotspot. Herein, this work synthesized C–SiO 2 for the deposition of Pd nanoparticles by a one-step method, and the obtained Pd/C–SiO 2 exhibits a superior FA dehydrogenation activity with a turnover frequency value of 1278 h −1 and a favorable stability with only a slight decrease in activity after five cycles.
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高影响因子
Journal of Cleaner Production
·
2023
·
IF 11.1
Zhenxiong Ye,Huidi Zhang,Xujie Chen,Lifeng Chen,Kunyapat Thummavichai,Xinpeng Wang,Toyohisa Fujita,Yuezhou Wei
Palladium is versatile in many industrial applications due to its distinct physicochemical properties . Due to the scarcity of natural resources and the growing market demand, palladium recovery from wastes such as spent catalysts is receiving increasing attention. Here, a silica-supported thiourea resin (SiPS-TU) was prepared and applied to separate Pd(II) from spent catalysts. The SiPS-TU was fabricated through in situ polymerization and post modification method using amorphous macroporous silica as the matrix. Experimental results suggested that the optimal acidity for the adsorption process was 0.1 M under selected range, and the uptake of SiPS-TU was affected by H + and Cl − . The adsorbent showed rapid sorption kinetics with an equilibrium attained in 30 min, while more than 3 h was required for the commercial D840 resin. Column tests showed that SiPS-TU had excellent dynamic separation property for Pd(II) in continuous process. Around 215 bed volumes (430 mL) of Pd(II) solution could be effective treated by the SiPS-TU bed before breakthrough at 4 mL/min, while D840 resin bed was less effective under equivalent conditions (20 mL). In view of its satisfactory adsorption performances, palladium was successfully separated from the catalyst leaching solution by SiPS-TU. XPS spectra and DFT calculations indicated that the adsorption mechanism of SiPS-TU for Pd(II) mainly involved anion exchange and coordination. In conclusion, this study provides a feasible material for palladium recovery from practical leachate.
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高影响因子
Journal of Physical Chemistry C
·
2021
·
IF 4.126
Pengchao Chen,Kaijie Li,Peijian Yan,Junyou Wang,Shenghu Zhou
In this work, Pd–FexOy hybrid nanoparticles encaged hollow mesoporous silica nanoreactors (Pd–FexOy@HMSNs) are synthesized, which features ∼3–4 nm Pd–FexOy hybrid nanoparticles inside ∼17 nm hollow cavities of ∼32 nm mesoporous silica nanoreactors. By employing Pd and Fe ions containing polymer micelles as templates for silica deposition, hollow mesoporous silica nanoreactors and the residence of functional nanoparticles inside hollow cavities are simultaneously obtained. Through adjusting the ratios of Pd2+/Fe3+ in micelles, various Pd–FexOy@HMSNs with different Pd/Fe ratios are synthesized and tested for reduction of nitroarenes with NaBH4. Relative to Pd@HMSNs, FexOy@HMSNs and their physical mixtures, Pd1–(FexOy)1/x@HMSNs illustrate a greatly enhanced catalytic performance for reductions of a series of substituted nitroarenes with NaBH4 to aminoarenes. The catalytic enhancement of Pd–FexOy@HMSNs is ascribed to the synergistic effect of Pd and FexOy as well as the confinement effect of functional nanoparticles inside hollow cavities.
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Wei Qi,Mengjie Li,Wei Chen,Jun Yang,Long Zhao
Radiation techniques, with their advantages of being clean, economical, and efficient, have been widely studied for the synthesis of nanocomposites. In this study, reduced graphene loading palladium nanoparticles (Pd/RGO) were prepared in situ in a single step at the phase interface of an ionic liquid (IL)-based microemulsion of these nanoparticles exposed to a high-energy electron beam. The influence of the radiation dose and initial mass ratio of graphene oxide (GO) and PdCl 2 were studied. In addition, the effect of the length of the alkyl chain of the IL on the shape and Pd nanoparticle content of Pd/RGO composites, as well as their electrochemical activity, were investigated in detail. The radiation dose did not affect the shape of the Pd nanoparticles but increased the Pd nanoparticle content of the Pd/RGO composites when the dose exceeded 80 kGy. The Pd nanoparticle content of the Pd/RGO composites decreased as the alkyl chain length of the ILs and the initial mass ratio of GO and PdCl 2 increased. Both the Pd nanoparticle content and their distribution in the Pd/RGO composites have a great influence on their electrochemical performance. Finally, Pd/RGO composites with excellent electrochemical activity were produced efficiently by using the radiation technique. This study provides a basis for the synthesis of carbon-based noble metal nanocomposites using a simple clean and efficient method.
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高影响因子
ChemCatChem
·
2021
·Vol. 13
·期 19
·4133-4141
·
IF 5.686
Lina Zhang,Bangjie Zhang,Peng Xue,Jiwei Li,Zhun Zhang,Yanling Yang,Shuai Wang,Jingdong Lin,Honggang Liao,Yong Wang,Yali Yao,Shaolong Wan,Haifeng Xiong
Graphical Room temperature oxidation : Pretreatment methods affect the nature of the Pd species and the reactivity of Pd/Al 2 O 3 in formaldehyde oxidation at room temperature. The steam treatment (H 2 O/Ar) increased the metal Pd dispersion, and generated more active hydroxyl groups, leading to the enhanced reactivity in formaldehyde oxidation. A Pd/Al 2 O 3 nanocatalyst was pretreated at 750 °C in air, Ar or H 2 O/Ar, respectively. The effect of these different pretreatments on the active species and reactivity of Pd/Al 2 O 3 in formaldehyde oxidation at room temperature was investigated. The pretreatment was found to affect both the phase transformation of PdO to Pd metal and the Pd dispersion, leading to different catalytic performances. We found that the Pd/Al 2 O 3 nanocatalyst pretreated in both Ar and H 2 O/Ar show 60 % and 100 % formaldehyde conversion at 25 °C, respectively, while the catalyst pretreated in air is not active under the same condition. Pretreatments in both Ar and H 2 O/Ar were found to facilitate the formation of metallic Pd on Pd/Al 2 O 3 catalyst, confirmed by both experiments and calculation based on the function of the equilibrium oxygen pressure and temperature. We further found that the catalyst pretreated in H 2 O/Ar has higher Pd dispersion and more surface OH groups compared to that pretreated in Ar, leading to improved activity in formaldehyde oxidation.
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高影响因子
ACS Applied Nano Materials
·
2020
·
IF 0
Wei Zhao,Shuang Liu,Huishu Wang,Jun Yang,Xinhan Chen
Heterogeneous Pd has been developed as a well-known catalyst for debenzylation reactions via hydrogenative C–N bond cleavage. However, the extensive applications are still limited owing to a high loading and usage amount of the noble metal. Herein, well-dispersed Pd nanocatalysts over TiO2 were explored with a deposition–precipitation method and characterized by FESEM, physical adsorption, XRD, TEM, and XPS. It was proposed that the ultrasmall and electron-rich Pd nanoparticles can be enhanced over TiO2 rather than C, Al2O3, or SiO2. As representatives, the debenzylations of hexabenzylhexaazaisowurtzitane (HBIW) and tetraacetyldibenzylhexaazaisowurtzitane (TADBIW), which are key steps for the synthesis of CL-20 with the highest energy and density, were selected to evaluate the catalytic performances. It was found that Pd/TiO2 exhibited considerably low usage with high yields in the debenzylation processes of not only HBIW (1 wt ‰) but also TADBIW (4 wt ‰). Meanwhile, the superior catalytic activities can be maintained in the different reaction scales and can be repeated for TADBIW hydrodebenzylation. Hence, Pd nanoparticles supported on TiO2 can be considered to be suitable catalysts for highly efficient catalytic synthesis for hydrogenative C–N bond cleavage.
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ENERGY & FUELS
·
2020
·
IF 3.421
Jun Hu,Mingxing Zhao,Bingxing Jiang,Shiliang Wu,Ping Lu
Direct hydrogenolysis of native lignin in biomass into monomeric phenols has received increasing attention. In this work, catalytic transfer hydrogenolysis of native lignin from birch, pine, and corn stalk was studied over a Ni–Pd bimetallic catalyst using isopropanol as the in situ hydrogen source. The bimetallic Ni50Pd50/SBA-15 exhibited higher activity than the monometallic counterparts in catalytic transfer hydrogenolysis of native birch lignin, affording 37.2 wt % monophenols at 245 °C after 4 h. 4-Propylsyringol had the highest yield of 18.9 wt % with a selectivity of 51%. Among the three biomass feedstocks, native lignin in birch gave the highest monophenol yield, which is 2.2 times that of native pine lignin (16.9 wt %) and 4.6 times that of native corn stalk lignin (8.1 wt %). FTIR and Py–GC MS analyses of the starting biomasses and the depolymerization solid products revealed that native birch lignin has the highest depolymerization efficiency with the least active lignin remaining.
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高影响因子
Functional Materials Letters
·
2020
·
IF 2
Kaicheng Yue,Zhaoqian Yan,Zhihao Sun,Anran Li,Lei Qian
In this work, graphitic carbon nitride (g-C 3 N 4 ) was modified by Pd nanoparticles (Pd-CN) to prepare an efficient cathode catalyst for Li-O 2 batteries. The specific surface area of g-C 3 N 4 was improved to 239.56 m 2 /g by two-steps thermal polymerization. Pd nanoparticles were loaded onto the g-C 3 N 4 by K 2 PdCl 4 reduction with NaBH 4 . The resulted Pd-CN composites were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscope, and transmission electron microscope. The results proved that g-C 3 N 4 showed three-dimensional layered and porous structure, and Pd nanoparticles were successfully supported on it. The Li-O 2 batteries using Pd-CN composites as cathode catalysts were assembled and tested. The maximum initial discharge specific capacity reached 26,614 mAh g − 1 at current density of 100 mA g − 1 . The electrodes remained large capacity under high current density, meaning excellent rate capability. Li-O 2 batteries containing Pd-CN cathode were continuously cycled for 70 cycles with no loss of capacity and obvious change in the terminal voltage. These electrochemical results indicated that the loading Pd nanoparticles effectively increased specific capacity, reduced overpotential and improved the cyclic stability. The Pd-CN composites are proved to be the promising cathode catalysts for Li-O 2 batteries.
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高影响因子
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