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.
研究领域:
环境科学
·
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Qiaoyi Zhang,Hongtan Cai,Xin Liu,Yulin Li,Meiyan Wang,Ge Gao,Zeshuo Meng,Haoteng Sun,Xiufeng Hao
A promising approach for powering hydrogen fuel cells (HFCs) involves the in-situ production of hydrogen from formic acid decomposition, with Pd-based catalysts recognized as effective for formic acid dehydrogenation. However, the immobilization of ultrafine palladium nanoparticles (Pd NPs) on catalytic supports presents a challenge and necessitates further investigation into their formation mechanism. We propose a coordination-induced strategy to understand the behavior of ultrafine Pd NPs formation based on multi-functional groups. To establish the structure–activity relationship for tunable Pd microenvironment and catalytic performance, we synthesized various polyacrylonitrile (PAN) carriers through hydrolysis and amidation modification. Molecular dynamics simulations confirmed that a stronger coordination-induced microenvironment facilitates the dispersion of Pd 2+ , suppressing aggregation and enhancing Pd loading. Our experimental results and density functional theory (DFT) calculations demonstrated that the catalytic activity of Pd@APAN(15_1%) with ultrafine Pd NPs (1.5 nm) exhibits over 10 times higher than that of Pd@PAN NPs with the turnover of frequency climbing from 112.6 h −1 to 1309.4 h −1 at 323 K. And Pd-imine and Pd-secondary amine moieties were verified to contribute to the creation of a favorable catalysis microenvironment. This study provides new insights into the design of modified supports with various groups to load well-dispersed and ultrafine Pd for highly efficient catalysts based on a coordination-induced strategy.
研究领域:
材料科学
·
催化化学
·
能源化学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2022
·
IF 6.14
Jian Wang,Yan Zhang,Yang Xu,Peiping Zhang,Qian Gao,Qing Liang,Wei Zhang,Wenqing Li,Ruifeng Guo,Bo Jin,Shiding Miao
The liquid-phase oxidation benzyl alcohol using hydrogen peroxide (H2O2) as an oxidant is a promising and green strategy for manufacturing aldehydes or/and ketones. Herein palladium (Pd) nanoparticles were impregnated in lumens of halloysite nanotubes by using ionic liquid (1-(2′-hydroxylethyl)-2,3-dimethylimidazolium chloride) as directing agents. On the basis of the asymmetric scroll-like structure of halloysite and the catalytic decomposition ability of Pd toward H2O2, the prepared catalyst (Pd-IL-HNTs) exhibited powerful self-propelled movement at an average speed of 276 ± 35 μm/s in 30.0 wt % H2O2 solution. The specific interaction between nanomotors and benzyl alcohol was observed as a consequence of self-moving behavior and hydrophobic interaction introduced by ionic liquid. With the synergistic coupling of the catalytic ability and powerful movement, Pd-IL-HNTs displayed outstanding catalytic benzyl alcohol oxidation performance. Compared to other nonpropelling catalysts using lamellar clay (montmorillonite and kaolinite) as supports, such HNT-based nanomotors registered superior catalytic performance, and the TOF value of 118.1 h−1 was obtained.
研究领域:
化学工程
·
催化科学
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Yaqi Chen,Linrong Zhang,Jin Wang,Huixiang Sheng,Kaili Wang,Junjie Wang,Shunhao He,Liuyingzi Yu,Gang Lu
Interface/emulsion catalysis is an effective approach for many organic and inorganic chemical reactions. Positioning catalysts at the interface is essential for highly efficient interface/emulsion catalysis. The sheet-like Janus nanostructures may have great advantages in stabilizing emulsions and improving reaction efficiency. In this work, by using a simple emulsion reaction and photodeposition, we successfully prepare the Janus nanosheets with opposite sides composed of AuNPs/PdNPs and reduced graphene oxide (rGO) respectively, referred to as AuNP-rGO/PdNP-rGO Janus nanosheets . Due to the distinct hydrophilicities on opposite sides, the prepared Janus nanosheets demonstrate high efficiency in emulsion stabilization and emulsion catalysis. By introducing the prepared PdNP-rGO and AuNP-rGO Janus nanosheets in emulsion reactions, highly efficient hydrogenation of p -nitroanisole and photocatalytic degradation of Nile red are demonstrated. This work provides a simple and cost-effective method to prepare Janus nanosheets and realize highly efficient emulsion reactions, and this strategy can be extended to promote many other interface/emulsion reactions.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Jiayu Jin,Shuozhen Hu,Xinsheng Zhang,Shigang Sun
Palladium is a promising formic acid electro-oxidation (FAO) catalyst due to its higher initial activity than platinum. However, suffering from the adsorption of hydrogen and CO-like species, the activity and stability of Pd are still unsatisfied. Herein, palladium nanoparticles deposited on carbon supported molybdenum trioxide (Pd–MoO 3 /C) is prepared with MoO 3 as the promoter for FAO. X-ray photoelectron spectroscopy analysis proves the close contact between Pd and MoO 3 , which generates the hydrogen spillover effect and forms the Pd–Mo structure. The hydrogen spillover effect enhances the desorption of hydrogen from Pd and facilitates the FAO activity. Both the spillover effect and Pd–Mo structure contribute to the removal of CO ad and facilitate the durability and anti-CO poisoning ability of the catalyst. With the optimized ratio of MoO 3 to carbon black, the Pd–MoO 3 /C-20 catalyst owns the best specific activity of 5.86 mA cm −2 , which is 1.86 times of Pd/C.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
iScience
·
2021
·
IF 5.458
Qing Zeng,Danye Liu,Hui Liu,Penglei Cui,Chaoquan Hu,Dong Chen,Lin Xu,Xiang Wu,Jun Yang
Summary Deliberately optimizing the d-band position of an active component via electronic and lattice strain tuning is an effective way to boost its catalytic performance. We herein demonstrate this concept by constructing core-shell Au@NiPd nanoparticles with NiPd alloy shells of only three atomic layers through combining an Au catalysis with the galvanic replacement reaction. The Au core with larger electronegativity modulates the Pd electronic configuration, while the Ni atoms alloyed in the ultrathin shells neutralize the lattice stretching in Pd shells exerted by Au cores, equipping the active Pd metal with a favorable d-band position for electrochemical oxygen reduction reaction in an alkaline medium, for which core-shell Au@NiPd nanoparticles with a Ni/Pd atomic ratio of 3/7 exhibit a half-wave potential of 0.92 V, specific activity of 3.7 mA cm −2 , and mass activity of 0.65 A mg −1 at 0.9 V, much better than most of the recently reported Pd-even Pt-based electrocatalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2020
·
IF 6.215
Shaoda Huang,Shuanglong Lu,Hongyin Hu,Binbin Cao,Huining Li,Fang Duan,Han Zhu,Hongwei Gu,Mingliang Du
Palladium-based catalyst represents one of the most promising candidates among all non-platinum oxygen reduction reaction (ORR) catalysts. However, it is still challenging to precisely engineering their morphology and composition . Herein, highly branched core-shell PdCu@Pd nanocrystals have been fabricated via a simple one-pot synthesis that co-directed by hydrogen gas and halide ions. Such unique PdCu@Pd nanocrystals exhibit prominent ORR activity, durability and methanol-tolerance in alkaline media owing to their core-shell composition , highly-branched structure and defect-rich surface. This work elucidates a facile strategy to design highly branched core-shell nanomaterials , shedding light on the exploration and optimization of novel non-platinum ORR catalysts.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Tian-Hong Jing,Yi-Ying Zhuang,Xiao-Xin Zhang,Jian-Guo Qian,Xiao-Li Zhao,Yong Lu,Hai-Jing Wang,Ye Liu
The elaborate control of regioselectivity regulated by the involved ligands with specific structural skeleton and compositions is always demanded in alkoxycarbonylation of alkenes. Herein, a series of pinwheel-like tridentate phosphine ligands with rotatable flexibility ( L3 ) or hard rigidity ( L5–L7 ) were synthesized and characterized for the first time, in which the incorporated three PPh 2 -fragments are located at meta-positions of phenyl groups. It was proved that the tridentate phosphine of L3 with the flexible configuration favorably corresponded to the linear regioselectivity with l/b ratio of 98/2, whereas L7 with the rigid configuration absolutely did favor to the branched regioselectivity with l/b ratio of 1/99. The presence of the three PPh 2 -frgaments in L3 did contribute to the remarkable performance of L3 -Pd(TFA) 2 system in terms of activity, linear regioselectivity and stability, subjected to 10-run recycling uses in anti -Markovnikov’s methoxycarbonylation of styrene without activity loss and Pd-black precipitation. In comparison, although the optimal L7 -Pd(MeCN) 2 Cl 2 system could catalyze Markovnikov’s alkoxycarbonylation of alkenes to afford the branched esters with excellent regioselectivity in the fresh use, its stability was too poor to support the recycling experiments. L3 -Pd(TFA) 2 and L7 -Pd(MeCN) 2 Cl 2 catalytic systems were both applicable to a wide range of substrates in alkoxycarbonylation of alkenes to afford the target esters in the isolated yields of 41–91 %, with the well maintained divergent regioselectivity.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
高影响因子
HELVETICA CHIMICA ACTA
·
2023
·Vol. 106
·期 5
·e202200203
·
IF 1.8
Peng Liu,Xin Zhang,Yuan-Yuan Huang,Geng-Wei Liu,Chen-Jie Li,Pin-Mei Yan,Ye-Yan Qin,Rong Guo,Si-Qi Wu,Yun-Yun Zeng,Peng-Bin Pan,Yuan-Gen Yao
High active Pd-based catalyst with low loading capacity for CO oxidative coupling with methyl nitrite (MN) to dimethyl oxalate (DMO) has aroused great interest in the large-scale production of DMO for the next hydrogenation to bring forth ethylene glycol (EG). Here, spinel composite oxide support, namely MgAl 2 O 4 , had been prepared through three different methods: solid combustion method (MAO-SC), hydrothermal method (MAO-HT) and co-precipitation method (MAO-CP), and further Pd nanoparticles were anchored to the surface of MgAl 2 O 4 through a simple wetness impregnation method. In the CO direct esterification to DMO reaction, the Pd/MAO-SC catalyst, which used MgAl 2 O 4 support prepared by solid combustion method, exhibited the highest intrinsic activity with Turnover frequency (TOF) value of 2.39 s −1 and DMO weight space-time yield (956.8 g⋅kg cat −1 ⋅h −1 ) with 44.1 % CO conversion and 97.8 % DMO selectivity, and showed negligible attenuation of activity during the process of continuous reaction for 100 h. The characterization results confirmed that abundant oxygen defect sites occurred in MAO-SC synthesized by combustion method not only can help to anchor the Pd nanoparticles with appropriate size and dispersion, but also can promote the interfacial electron transfer from MgAl 2 O 4 support to Pd nanoparticles, thus significantly enhancing the metal-support interaction (MSI) and providing more CO bridge-adsorption sites that is favorable for the CO oxidative coupling with MN to DMO reaction.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Dong Li,Tianyi Sun,Lu Wang,Na Wang
To improve the electro-catalytic degradation efficiency of the cathode in electrochemical advanced oxidation processes , MnO 2 modified Nano-graphite (MnO 2 /Nano-G) and Pd loaded Foam-Ni (Foam-Ni/Pd) composites were prepared by the chemical redox and electro-deposition methods, respectively, and a two-layer type MnO 2 /Nano-G|Foam-Ni/Pd composite cathode was prepared with the chitosan as a binder. The composites were characterized by X-ray diffraction, scanning electrons microscopy and X-ray photoelectron spectroscopy. Results showed that the mix-crystal structural MnO 2 (α-MnO 2 and γ-MnO 2 ) nanorods with length of 80–200 nm and width of 20–50 nm were uniformly loaded on the Nano-G surface, and the three-dimensional Pd° metal trees/crystals were tightly deposited on the Foam-Ni substrate. The as-prepared cathode was applied to the electro-catalytic degradation of phenol wastewater, and the reaction parameters were optimized. Compared with MnO 2 /Nano-G|Foam-Ni and Nano-G|Foam-Ni cathodes, the degradation efficiency of phenol by MnO 2 /Nano-G|Foam-Ni/Pd cathode was significantly improved. The removal efficiencies of phenol and total organic carbon (TOC) by MnO 2 /Nano-G|Foam-Ni/Pd cathode reached 98.7% and 85.3% after 120 min electrolysis under oxygen aeration condition, respectively. The optimal reaction parameters were current density of 39 mA cm −2 , electrolyte (Na 2 SO 4 ) concentration of 0.1 mol L −1 , electrode distance of 4 cm and initial pH of 7. By determining the variations of H 2 O 2 and OH content in the cathode chamber, it was found that Pd metal crystals improved the reduction of O 2 to H 2 O 2 and MnO 2 nanorods accelerated the dissociation of H 2 O 2 to OH, producing more H 2 O 2 and OH to oxidize phenol and eliminate TOC in wastewater. The results in this study provide useful information for the control of refractory organic pollutants with electrochemical advanced oxidation in wastewater treatment .
研究领域:
环境科学
·
电化学工程
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2018
·
IF 0
Fengwei Zhang,Chunlan Ma,Shuai Chen,Jianfei Zhang,Zhihong Li,Xian-Ming Zhang
Chemoselective hydrogenation of quinolines is often subjected to the problems of leaching and poisoning of catalytic active site as well as harsh reaction conditions. Developing a novel and high-performance heterogeneous catalyst is of paramount importance yet a huge challenge. Herein, we report a facile and efficient strategy for preparing the large surface area and highly N-doped hierarchical porous carbon anchored tiny Pd NPs catalyst, in which the low-cost chitosan, nitrogen-rich ionic liquids are served as composite precursors and KZ molten salt as friendly pore-forming agent. And a series of Pd@CIL-T (C refers to chitosan, IL refers to ionic liquid, T = 600–900 °C) catalysts are successfully fabricated via pyrolyzing aforesaid composites at different temperatures followed by anchoring the highly dispersed and small-sized Pd NPs on their surface. Among all the prepared catalysts, Pd@CIL-900 exhibits the optimal catalytic performance towards the selective hydrogenation of quinoline under extremely mild conditions (0.6 mol% Pd, 0.1 MPa H 2 and 50 °C). The kinetic experiments further reveal that such hydrogenation is subject to a pseudo-first order reaction and the apparent activation energy is as low as 41.1 kJ/mol, demonstrating excellent hydrogenation reaction rate. Moreover, the catalytic activity and selectivity are well maintained even after being reused for fifth reaction cycles.
研究领域:
化学
·
催化材料
·
纳米技术
✓ 已验证
DOI
Chemistry-An Asian Journal
·
2017
·Vol. 12
·期 23
·3039-3045
·
IF 4.083
Yan Sun,Tao Wang,Ang Li,Ling Zhang,Qisheng Huo,Zhen-An Qiao
Graphical A simple and straightforward route is reported to knit benzene heterocycles to synthesize a series of hierarchical porous polymers with high surface area and abundant N sites. The N-doped porous polymers can effectively stabilize ultra-small Pd nanoparticles for solvent-free catalysis. Hierarchical porous polymers with more than one pore size distributions can effectively support noble metal catalysts and circumvent the limitation of the diffusion of the reactants, and thus exhibit both excellent catalytic activity and superior diffusive properties. Herein, we report a simple one-step Friedel–Crafts reaction to knit a series of benzene heterocycle monomers, such as indane, indoline, indole and tetrahydronaphthalene to obtain hierarchical porous polymers with high surface areas and/or abundant N sites. These polymers can be directly used to immobilize Pd ions, and stabilize Pd nanoparticles during the thermal reduction process to obtain Pd/polymer catalysts. In particular, indoline- and indole-based polymers with high N content up to 7 wt % exhibit outstanding ability to stabilize uniform ultrasmall Pd nanoparticles. The obtained Pd-polymers exhibit excellent catalytic activity in the solvent-free oxidation of benzyl alcohol with O 2 .
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）