JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2023
·
IF 9.9
Zhen He,Qiaohui Duan,Chengming Wang,Lingwen Liao
A highly active surface can endow the electrocatalysts with extraordinary catalytic performances. However, it remains challenging to tailor the atomic packing characteristics and thus the physical and chemical characteristics of the electrocatalysts . Herein, penta-twinned Pd nanowires (NWs) with abundant high-energy atomic steps (i.e., stepped Pd) are synthesized by seeded synthesis on Pd NWs enclosed by (1 0 0) facets. Benefiting from the catalytically active atomic steps, such as [ n (1 0 0) × m (1 1 1)] on the surface, the resultant stepped Pd NWs can work as an effective electrocatalyst for the ethanol oxidation reaction (EOR) and ethylene glycol oxidation reaction (EGOR), which are essential anode reactions in direct alcohol fuel cells (DAFCs). Compared with commercial Pd/C, the Pd nanowires bound by (1 0 0) facets and atomic steps both display enhanced catalytic activity and stability towards the EOR and EGOR. Importantly, the mass activities of the stepped Pd NWs toward the EOR and EGOR are 6.38 and 7.98 A mg Pd −1 , which are 3.1 and 2.6 times those of Pd NWs enclosed by (1 0 0) facets, respectively. Besides, our synthetic strategy also enables the formation of bimetallic Pd-Cu nanowires with abundant atomic steps. This work not only demonstrates a simple yet effective strategy to obtain mono- or bi-metallic nanowires with abundant atomic steps, but also highlights the significant role of atomic steps for boosting the activity of electrocatalysts.
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高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Bin Yao,Jianqi Ye,Chen Wang,Wenjing Mu,Fei Liu,Dan Wen
Noble metal aerogels with unique porous structure have demonstrated tremendous potentials in electrocatalysis due to its excellent electrical conductivity, large specific surface area, high porosity, and prominent activity. However, the traditional two-step synthetic method is time-consuming and complicated, limiting its development and application. In this work, we synthesized Pd-CoO x aerogels simply and quickly by in situ electrochemical reduction strategy without additional organic ligands. Interestingly, introducing Co to form composite aerogels significantly improved the catalytic performance of Pd due to the synergy between Pd and Co. The optimized Pd 3 -(CoO x ) 1 aerogel exhibited excellent electrocatalytic activities in alcohol oxidations after the in situ electrochemical activation. Specifically, the mass activities of the Pd 3 -(CoO x ) 1 aerogel for methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR) reached 4.94 A mg Pd −1 and 8.67 A mg Pd −1 , respectively, which are 10.5 times and 7.4 times higher than those of the commercial Pd/C. These findings may offer a facile synthetic strategy for composite aerogel catalysts with high electrocatalytic performance.
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MOLECULES
·
2023
·Vol. 28
·期 5
·2335
·
IF 4.6
Hongquan Kang,Jianzhou Wu,Baohui Lou,Yue Wang,Yilin Zhao,Juanjuan Liu,Shihui Zou,Jie Fan
The rational regulation of catalyst active sites at atomic scale is a key approach to unveil the relationship between structure and catalytic performance. Herein, we reported a strategy for the controllable deposition of Bi on Pd nanocubes (Pd NCs) in the priority order from corners to edges and then to facets (Pd NCs@Bi). The spherical aberration-corrected scanning transmission electron microscopy (ac-STEM) results indicated that Bi2O3with an amorphous structure covers the specific sites of Pd NCs. When only the corners and edges of the Pd NCs were covered, the supported Pd NCs@Bi catalyst exhibited an optimal trade-off between high conversion and selectivity in the hydrogenation of acetylene to ethylene under ethylene-rich conditions (99.7% C2H2conversion and 94.3% C2H4selectivity at 170 °C) with remarkable long-term stability. According to the H2-TPR and C2H4-TPD measurements, the moderate hydrogen dissociation and the weak ethylene adsorption are responsible for this excellent catalytic performance. Following these results, the selectively Bi-deposited Pd nanoparticle catalysts showed incredible acetylene hydrogenation performance, which provides a feasible perspective to design and develop highly selective hydrogenation catalysts for industrial applications.Keywords:acetylene hydrogenation;active sites;selective deposition;palladium;bismuth
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高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 13
·4200-4206
·
IF 4
Jianxin Lv,Linghui Zhang,Lianxi Si,Hui Li,Wenbo Zhao,Fei An,Xia Feng,Shi Hu
Materials with accurate and durable gas detection are essential for gas sensors. We developed a facile and effective method to deposit Pd onto WO3 nanosheets and used the samples for hydrogen gas sensing. The combination of the 2D ultrathin nanostructure of WO3 and the spillover effect of Pd enables a detection concentration down to 20 ppm of hydrogen and high selectivity against other gases including methane, butane, acetone, isopropanol, etc. Moreover, the durability of the sensing materials was testified through 50 cycles of exposure to 200 ppm of hydrogen. These outstanding performances are mainly attributed to a homogeneous and tenacious decoration of Pd on the surface of WO3 nanosheets, providing an attractive choice for practical applications.
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Journal of Physical Chemistry C
·
2023
·
IF 3.7
Xiaoyu Zhao,Wei Ran,Zixuan Wang,Jiefang Sun,Rui Liu,Jingfu Liu
Core–shell nanocatalysts have shown superior catalytic activity than monometallic catalysts. However, these metastable materials are susceptible to structural changes during catalysis. Comprehending the evolution of surface sites and their stability under different reaction conditions is crucial for designing durable and highly active core–shell nanocatalysts. Herein, structural transformation of the atomic layer thickness of Pd shells on Au nanocubes in different electrolytes at various electrochemical windows was investigated by a combination of cyclic voltammetry (CV), surface-enhanced Raman spectroscopy (SERS) of adsorbed probe molecules, and elemental analysis. Pd sites are stable under basic and neutral conditions but experience severe structure evolution under acidic conditions. Pd atoms that are directly coordinated by Au atoms, upon oxidation at evaluated potential, transform into Pd ions via the reaction with H+ which would also be adsorbed on the Au sites. These Pd ions are easily coreduced with the formed Au ions into surface alloys in the backward CV scan. In contrast, Pd atoms in the thick Pd overlayer (>1 monolayer) are likely to dissolute into the electrolyte solution and leach. SERS revealed that the change of Pd sites primarily occurred at contiguous Pd sites and isolated Pd sites were relatively stable. This evolution mechanism provides new insight into the rational design of efficient and stable catalysts and is expected to promote further application of core–shell nanocatalysts.
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Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Yuan Chen,Yuancai Chen,Yexia Qin
In the present study, we found that nanoparticles (Pd-NPs) were biosynthesized by Bacillus wiedmannii MSM ( B. wiedmannii MSM) with endogenous carbon under O 2 condition, and more favorablity under N 2 purging condition. XRD results indicated that crystal planes of Pd-NPs were attributed to Pd 0 (111), Pd 0 (200), Pd 0 (220), and Pd 0 (311), respectively. TEM and STEM-EDX results showed that the bio-reduction of Pd (II) ( k pd,1 =4.799 min −1 ) occurred predominately in periplasm space. FTIR results showed that the -COOH, -OH, and -NH 2 were the main groups participating in the removal of Pd (II). The aerobic reduction of Pd (II) by B. wiedmannii MSM was proposed, including extracellular superoxide radicals produced by NAD(P)H oxidases , endogenous electron donors, and O 2 -insensitive hydrogenase. These studies provide new methods and insights for reduction of Pd (II).
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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.
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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.
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高影响因子
CATALYSIS LETTERS
·
2018
·Vol. 148
·期 4
·1190-1201
·
IF 2.911
Zhang Yuanyuan,Yi Qingfeng,Deng Zhongliang,Zhou Xiulin,Nie Huidong
Abstract Multi-walled carbon nanotube (CNT) supported Pd–Ag–Sn nanocatalysts including Pd/CNT, Pd 7 Ag 3 /CNT, Pd 7 Sn 2 /CNT, Pd 7 Ag 1 Sn 2 /CNT, Pd 7 Ag 2 Sn 2 /CNT and Pd 7 Ag 3 Sn 2 /CNT, have been prepared in a mixture solution of ethylene glycol and water by NaBH 4 reduction method. The samples have been characterized by using scanning electron microscopy, transmission election microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Compared to the Pd/CNT and Pd 7 Ag 3 /CNT catalysts, metal particles of the ternary Pd 7 Ag 2 Sn 2 /CNT catalyst are more uniformly dispersed on the surface of CNTs and present the size of ca. 2.4 nm. Both binary Pd–Ag and ternary Pd–Ag–Sn catalysts exhibit the alloying of Pd and Ag. Electrochemical activities of the prepared catalysts for ethanol oxidation in alkaline media were investigated by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy. Results show that Pd 7 Ag 2 Sn 2 /CNT catalyst reveals the highest current density of ethanol oxidation among the prepared catalysts and presents a high steady-state current density for ethanol oxidation from CA measurement, which is 33 times higher than the commercial Pd/C. Also, Pd 7 Ag 2 Sn 2 /CNT and Pd 7 Ag 3 Sn 2 /CNT catalysts show a large ethanol oxidation peak current density (against Pd loading) of 2.29 and 2.30 A mg −1 , indicating the high usage efficiency of Pd particles for ethanol oxidation. Graphical Abstract
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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.
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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.
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CRYSTENGCOMM
·
2017
·Vol. 19
·期 46
·6964-6971
·
IF 3.474
Aleksei Chalgin,Fenglei Shi,Fan Li,Qian Xiang,Wenlong Chen,Chengyi Song,Peng Tao,Wen Shang,Tao Deng,Jianbo Wu
Elemental composition, dimensionality and morphology are the main factors that influence the catalytic activity and stability of platinum-based and noble metal alloy nanocatalysts. Herein, we present a facile and cost-efficient approach to synthesize ternary alloy Pt–Pd–Ag nanoflowers by co-reduction of the metal precursors in aqueous solutions in a suitable molar ratio, involving hexamethylenetetramine as a structure-directing agent and ascorbic acid as a reducing agent. Both the presence of the aforementioned agents and the interaction between the component metals allow good control over the anisotropic growth of the ternary alloy nanostructure. The as-prepared nanocomposite demonstrates superior electrocatalytic activity towards the oxygen reduction reaction in acidic medium, compared with commercial Pt/C (20 wt%) and Pd/C (10 wt%) catalysts, as well as sufficiently good stability, as demonstrated by the accelerated durability test. The electrocatalytic activity of irregularly shaped nanoparticles of the same elemental composition was also measured, which revealed that the nanoflowers were superior catalysts owing to their specific morphological characteristics. Moreover, the nanoflowers displayed a relatively low electrochemical surface area decay (from 100% to 80.82%) due to their three-dimensional open-framework surface which can limit the aggregation of individual particles.
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