Small
·
2024
·Vol. 20
·期 32
·2311840
·
IF 13
Xinhua Zhao,Lingling Du,Xiaxia Xing,Zhenxu Li,Yingying Tian,Xiaoyu Chen,Xiaoyan Lang,Huigang Liu,Dachi Yang
With the recently-booming hydrogen (H 2 ) economy by green H 2 as the energy carriers and the newly-emerged exhaled diagnosis by human organ-metabolized H 2 as a biomarker, H 2 sensing is simultaneously required with fast response, low detection limit, and tolerant stability against humidity, switching, and poisoning. Here, reliable H 2 sensing has been developed by utilizing indium oxide nanocubes decorated with palladium and gold nanodots (Pd–Au NDs/In 2 O 3 NCBs), which have been synthesized by combined hydrothermal reaction, annealing, and chemical bath deposition. As-prepared Pd–Au NDs/In 2 O 3 NCBs are observed with surface-enriched NDs and nanopores. Beneficially, Pd–Au NDs/In 2 O 3 NCBs show 300 ppb-low detection limit, 5 s-fast response to 500 ppm H 2 , 75%RH-high humidity tolerance, and 56 days-long stability at 280 °C. Further, Pd–Au NDs/In 2 O 3 NCBs show excellent stability against switching sensing response, and are tolerant to H 2 S poisoning even being exposed to 10 ppm H 2 S at 280 °C. Such excellent H 2 sensing may be attributed to the synergistic effect of the boosted Pd–Au NDs’ spillover effect and interfacial electron transfer, increased adsorption sites over the porous NCBs’ surface, and utilized Pd NDs’ affinity with H 2 and H 2 S. Practically, Pd–Au NDs/In 2 O 3 NCBs are integrated into the H 2 sensing device, which can reliably communicate with a smartphone.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xuan Huang,Ming Yi,Kewen Tang
To address resources shortage and environmental degradation, noble metal recovery from e-waste is in desperate need. Herein, to achieve selective extraction of gold (Au) and palladium (Pd) from practical e-waste, a series of tridentate thioether extractants are designed with ester functional groups at both ends of the thioether. By varying the chain length of the ester alkyl, the relationship between extractant structure and performance is further explored. The results indicate that the as-introduced tridentate structure facilitate the Au(III) and Pd(II) extraction, demonstrating a complex mechanism involving both coordination substitution and ion association. Notably, the extractant with the shortest carbon chain length and smallest molecular weight delivers outstanding extraction capacities of 920.2 mg/g for Au(III) and 280.7 mg/g for Pd(II). More importantly, it exhibits superior selectivity (∼100 %) for Au(III) and Pd(II) in complex metal solutions. This work guides the design of thioether-based extractants for sustainable recovery of noble metal from practical e-waste.
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高影响因子
Journal of Environmental Sciences
·
2021
·
IF 5.565
Chang Cui,Yan Zhang,Wenpo Shan,Yunbo Yu,Hong He
Alumina supported Pd catalyst (Pd/Al 2 O 3 ) is active for complete oxidation of methane, while often suffers transient deactivation during the cold down process. Herein, heating and cooling cycle tests between 200 and 900°C and isothermal experiments at 650°C were conducted to investigate the influence of NO x on transient deactivation of Pd/θ-Al 2 O 3 catalyst during the methane oxidation. It was found that the co-fed of NO alleviated transient deactivation in the cooling ramp from 800 to 500°C, which was resulted from the in situ formation of NO 2 during the process of methane oxidation. Over the Pd/θ-Al 2 O 3 , thermogravimetric analysis and O 2 temperature programmed oxidation measurements confirmed that transient deactivation was due to the decomposition of PdO particles and the hysteresis of Pd reoxidation, while the metal Pd entities were less active for methane oxidation than the PdO ones. CO pulse chemisorption and scanning transmission electron microscopy characterizations rule out the NO 2 effect on Pd size change. Powder X-ray diffraction and X-ray photoelectron spectroscopy characterizations were used to obtain palladium status of Pd/θ-Al 2 O 3 before and after reactions, indicating that in lean conditions at 650°C, the presence of NO 2 increases the content of active PdO on the catalyst surface, thus benefits methane oxidation. Homogeneous reaction between CH 4 , O 2 , and NO x may be partially responsible for the alleviation above 650°C. The interesting research of alleviation in transient deactivation by NO x , the components co-existing in exhausts, are of great significance for the application.
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高影响因子
JOURNAL OF CATALYSIS
·
2021
·
IF 7.92
Zhi-Feng Jiao,Ya-Ming Tian,Xiao-Ning Guo,Udo Radius,Holger Braunschweig,Todd B. Marder,Xiang-Yun Guo
A highly efficient photocatalytic protocol for borylation of alkyl bromides and chlorides with graphene supported Cu/Pd alloy nanoparticles as a heterogeneous catalyst is reported. This photocatalytic system operates with visible light in air, providing a wide range of primary and secondary alkyl halides with B 2 pin 2 or B 2 neop 2 in high yields at low temperatures, thereby demonstrating its broad utility and functional group tolerance. The high performance is attributed to a synergistic effect of localized surface plasmon resonance (LSPR) of Cu and charge transfer from Cu to Pd due to the alloy surface charge heterogeneity. Transfer of energetic electrons from Pd to electrophilic alkyl halides lead to the formation of the alkyl radicals, which quickly react with a nucleophilic adduct of a diboron compound with base adsorbed on the positively charged Cu sites to form the corresponding borylation product.
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高影响因子
Journal of the American Chemical Society
·
2022
·
IF 16.383
Dan Wang,Faxing Shi,Jesil Jose,Yanfang Hu,Cancan Zhang,Aonan Zhu,Roland Grzeschik,Sebastian Schlücker,Wei Xie
The central dilemma in label-free in situ surface-enhanced Raman scattering (SERS) for monitoring of heterogeneously catalyzed reactions is the need of plasmonically active nanostructures for signal enhancement. Here, we show that the assembly of catalytically active transition-metal nanoparticles into dimers boosts their intrinsically insufficient plasmonic activity at the monomer level by several orders of magnitude, thereby enabling the in situ SERS monitoring of various important heterogeneously catalyzed reactions at the single-dimer level. Specifically, we demonstrate that Pd nanocubes (NCs), which alone are not sufficiently plasmonically active as monomers, can act as a monometallic yet bifunctional platform with both catalytic and satisfactory plasmonic activity via controlled assembly into single dimers with an ∼1 nm gap. Computer simulations reveal that the highest enhancement factors (EFs) occur at the corners of the gap, which has important implications for the SERS-based detection of catalytic conversions: it is sufficient for molecules to come in contact with the “hot spot corners”, and it is not required that they diffuse deeply into the gap. For the widely employed Pd-catalyzed Suzuki–Miyaura cross-coupling reaction, we demonstrate that such Pd NC dimers can be employed for in situ kinetic SERS monitoring, using a whole series of aryl halides as educts. Our generic approach based on the controlled assembly into dimers can easily be extended to other transition-metal nanostructures.
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MACROMOLECULAR MATERIALS AND ENGINEERING
·
2013
·Vol. 299
·期 3
·361-367
·
IF 2.338
Weining Sun,Xiaofeng Lu,Yanpeng Xue,Yan Tong,Ce Wang
In this report, CoFe 2 O 4 /Polypyrrole (PPy)/Pd ternary composite nanofibers are fabricated through a one-step redox reaction between pyrrole and Na 2 PdCl 4 in the presence of electrospun CoFe 2 O 4 nanofibers in ethylene glycol (EG). The generation of Pd nanoparticles is accompanied by the formation of PPy on the surface of electrospun CoFe 2 O 4 nanofibers during the redox reaction. The as-prepared CoFe 2 O 4 /PPy/Pd composite nanofibers may be used as efficient catalysts for the p -nitrophenol hydrogenation with an apparent rate constant ( k app ) of about 13.2 × 10 −3 s −1 . The CoFe 2 O 4 /PPy/Pd composite nanofibers show good magnetic properties, which can be readily recycled under an external magnetic field.
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高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2022
·Vol. 135
·期 6
·3243-3256
·
IF 1.843
Zhou Lin,Wang Ruo-Bing
Nitrogen doped mesoporous carbon (N-MPC)-supported monometallic and bimetallic catalysts were synthesized by using hydrothermal and impregnation method, and the catalytic activity of the catalyst to carbon–carbon bond-forming reactions (Suzuki, Heck and Sonogashira reactions) was studied. The bimetallic catalyst Pd-Ni@N-MPC with high Ni to Pd atomic ratios showed highly activity in the C–C coupling reactions of aryl halide under optimized condition. In contrast to their monometallic counterparts, such Pd-Ni@N-MPC catalyst not only show higher catalytic activity but also show more economic and stable. The catalysts were characterized by powder X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope and transmission electron microscopy, which demonstrated that the Pd–Ni NPs highly dispersed and possessed uniform size.
Graphical abstract
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Qiao Wang,Wei Wang,Boyin Yan,Wenxin Shi,Fuyi Cui,Ce Wang
The present development gives an insight into the effect of the distribution of bimetallic sites in denitrification. A highly-dispersed Pd-Cu bimetallic catalyst supported by titanium dioxide nanofibers (Pd-Cu/TiO 2 ) was in situ fabricated by electrospinning and subsequent calcination and chemical reduction, and then applied in the catalytic reduction of water phase nitrate (NO 3 − ) to nitrogen gas (N 2 ). Compared with ex situ Pd-Cu impregnated catalyst, the in situ Pd-Cu/TiO 2 nanofibers exhibited the high nitrate removal efficiency, selectivity and fast kinetics (about twice that of impregnated ones). These good catalytic performances are mainly benefited from increased active sites and raised ratio of nitrogen to hydrogen on them, which are brought about by the well-dispersed and closely connected Pd-Cu bimetallic nanoparticles in TiO 2 nanofiber matrix. Moreover, the in situ nanofiber matrix provides a physical barrier to inhibit bimetallic nanoparticles movement, aggregation and leakage from the support into water, and hence significantly enhances the recyclability for nitrate reduction.
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高影响因子
CATALYSIS COMMUNICATIONS
·
2016
·
IF 3.389
Xingrui Fu,Yue Liu,Weiyuan Yao,Zhongbiao Wu
The catalytic performances of Pt-Pd/MCM-41 bimetallic catalysts prepared by one-step synthesis method were investigated for total toluene oxidation in this paper. The experimental results demonstrated that Pt-Pd/MCM-41 was of superior catalytic activity comparing to the monometallic Pt/MCM-41 or Pd/MCM-41 catalysts with the same metallic content, yielding an almost 100% conversion at 180 °C. The following characterization results indicated that the bimetallic catalyst possessed a higher surface Pt(0) content and smaller doped metal size owing to the synergistic effect of the two noble metals, resulting in the improvement of oxygen adsorption capacity and the reducibility.
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高影响因子
Molecular Catalysis
·
2020
·
IF 3.687
Yaqi Qu,Yan Wang,Jianwei Li,Qiuxia Xu,Xin Liang,Angran Jiang
CO coupling to dimethyl oxalate (DMO) has been considered as the most important part in industrial production of ethylene glycol (EG). Five kinds of Pd nanoparticles with various morphologies were successfully synthesized by liquid-phase reduction. The exposed crystal planes of these Pd nanoparticles were identified and quantified. The corresponding supported Pd/α-Al 2 O 3 showed excellent catalytic activities for CO coupling reaction and the catalysts including Pd icosahedra can enhanced the selectivity of DMO to 98% and remained unchanged for 50 hours. The characterization results illustrated that the exposure of Pd (111) facets enhanced the intensities of bridged CO, which contributed to the high performance of the Pd-based catalysts. DFT calculations revealed CO adsorbed on Pd (111) facets had higher binding energies. This work systematically discussed the influence of Pd morphologies. Experimental and theoretical results confirmed that the Pd (111) facets showed better catalytic activities for CO coupling reaction.
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高影响因子
Biomaterials Science
·
2020
·Vol. 8
·期 17
·4757-4766
·
IF 6.183
Jing Zhang,Dan Liu,Jiale Liu,Yanfeng Han,Haiyan Xu,Xigang Leng,Deling Kong,Lanxia Liu
Combined blockades of CTLA-4 and PD-1 can yield better overall complementary clinical outcomes than individual blockades, but the response rates are still relatively low. To investigate the anti-tumor effects of various combined strategies, we designed various spherical nucleotide nanoparticles (SNPs) loaded with CTLA-4 aptamer (cSNPs), PD-1 siRNA (pSNPs) or both (hybrid SNPs, or hSNPs). The results demonstrated that hSNPs could promote significantly stronger anti-tumor immune responses in a nonredundant fashion than the mixture of pSNPs and cSNPs (pSNPs & cSNPs). We reasoned that this is because all individual immune cells could receive both CTLA-4 and PD-1 blockades when they engulfed hSNPs, but it is much less likely that individual immune cells could receive both CTLA-4 and PD-1 blockades as many of them may not take both pSNPs and cSNPS from pSNPs & cSNPs. Further results revealed that the synergistic immune stimulatory effects of CTLA-4 and PD-1 blockades in the form of hSNPs were at least partly through regulating the immune suppressive function of both Tregs and TIM3+ exhausted-like CD8 T cells and allowing effector T cells to expand. This mechanism is not identical to earlier reported mechanisms of CTLA-4 and PD-1 blockades.
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产品关联
DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2025
·
IF 3.3
Yonghui Ye,Yu Zhang,Xintong Yan,Gong Ning,Shi Hu
A facile one-step method is employed to synthesize carbon-supported Pd–Pb binary metal catalysts for the ethanol oxidation reaction (EOR) in alkaline electrolytes. A variety of characterization techniques have demonstrated that the alloying of Pd with Pb alters the electronic structure and induces lattice expansion. Electrochemical tests for the EOR in alkaline electrolytes demonstrated that the Pd3Pb/C catalyst exhibited the highest mass activity (3.59 A mgPd−1) and specific activity (17.97 mA cm−2), which are 4.6 and 4.7 times those of the Pd/C catalyst prepared by the same method, respectively. The intercalation of lead atoms has altered both the lattice and the electronic structure of palladium, leading to opposing shifts in the d-band center that collectively optimize the adsorption strength of CO* and OH*, key intermediates of the EOR. Consequently, the Pd3Pb/C electrocatalyst exhibits significant EOR catalytic activity. This study provides a viable implementation plan and analytical strategy for optimizing palladium-based catalysts with non-noble metals by integrating electronic transfer, bifunctional effects, and d-band center adjustments for bimetallic catalysts.
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产品关联
DOI
PubMed
高影响因子
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