CHEMPHYSCHEM
·
2022
·Vol. 24
·期 7
·e202200505
·
IF 3.52
Xujun Ma,Donghui Wang,Jianan Wu,Bin Zhao,Feng Chen
Graphical Fe 3+ doping was utilized to promote the formation of oxygen vacancies and improve the interaction between TiO 2 and atomic Pt. Single Pt atoms anchored on the oxygen vacancy sites of Fe−TiO 2 effectively modify the local energy band structure of TiO 2 , and thus significantly boost the catalytic performance of either the intrinsic or the sensitized photocatalytic process for Pt/Fe−TiO 2 . Single atomic site catalysts display the maximal atom-utilization efficiency, unique structural properties, and remarkable enhancements on catalytic activity. Herein, single Pt atoms loaded Fe−TiO 2 catalysts were prepared. Fe 3+ doping leads to the formation of oxygen vacancies and improve the interaction between TiO 2 and Pt. Single Pt atoms are thus anchored and effectively modify the local energy band structure of TiO 2 . The optimized local band structures improve the intrinsic photoexcitation of Pt/Fe−TiO 2 , promote the separation of photogenerated carriers, and extend the lifetime of photogenerated carriers. Meanwhile, the electrons transfer from the excited dyes to the conduction band edge of Pt/Fe−TiO 2 is also facilitated due to the shift-down of the conduction band edge. Therefore, with the increase of the Pt content (till up to 0.6 wt%), the photocatalytic performance of Pt/ Fe−TiO 2 with the confined single Pt atoms is significantly boosted in either the intrinsic or the sensitized photocatalytic process.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Materials Interfaces
·
2022
·Vol. 9
·期 26
·2201263
·
IF 6.389
Mingan Zhou,Minghao Liu,Qiyang Miao,Hengfu Shui,Qing Xu
Oxygen reduction reaction (ORR) plays key roles in fuel cells and metal air batteries. Covalent organic frameworks (COFs)-derived carbons have been utilized for catalyzing ORR. However, the activity and selectivity for these catalysts in the acidic medium is still under improved. In this work, Pt atoms and uniform Pt nanoparticles supported by standing carbons are derived from a three-dimensional COF. With increasing the contents of Pt ions, the corresponding particle sizes show obvious decrease, and thus resulting in higher catalytic activity. The synergetic roles between Pt atoms and nanoparticles with average sizes of 6.19 nm make catalyst show remarkable activity toward ORR, with onset potential and half-wave potential of 0.98 and 0.85 V (vs RHE) in the acidic medium, which are 70 and 40 mV more positive than those of Pt/C, respectively. This work provides a new insight for developing COFs in energy storage and conversion systems.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2024
·
IF 4
Changhui Liang,Kairui Liu,Huixiang Li,Xiaoqiang Zhang,Jun Shen,Z. Conrad Zhang
Single atom catalysts (SACs) offer high atom efficiency with highly selective reaction pathway. Various strategies have been developed to synthesize SACs, among which thermally stable metal centers are usually in high oxidation while they are susceptible to facile sintering in reduced state or under reducing conditions. One of the strategies developed very recently to achieve stable zero valent metal atoms is based on the selection of ligands with moderate coordination strength with the metal center. In this work, the crucial importance of ligand to the stability of single Pt 0 atoms is investigated. While HCl and diether have been found to be able to stabilize single Pt 0 atoms by forming Pt 1 @HCl adducts, HBr coordinated Pt single atom (Pt 1 @HBr) obtained by simply exchanging HCl with HBr shows increased thermal stability over the Pt 1 @HCl under H 2 atmosphere at elevated temperature, as evidenced by DRFITs of CO chemisorption and HRTEM. This work offers a facile approach to tune the stability of Pt single atoms while keeping the structure of active sites of single atom center to achieve excellent catalytic performance, using hydrosilylation in the demonstrative studies.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2024
·
IF 3.7
Zhijun Wang,Jingjing Wu,Limin Liu,Wenchi Wu,Yinfeng Wang,Haigen Huang,Fei Deng,Xuexia Liu
Currently, platinum (Pt)/carbon support composite materials have tremendous application prospects in the hydrogen evolution reaction (HER). However, one of the primary challenges for boosting their performance is designing a substrate with the desired microstructure. Herein, the intact hollow carbon spheres (HCSs) were prepared via template method. Based on the morphology variation of the as-prepared HCSs-x, we conjectured that the polydopamine (PDA) core was generated first and then slowly grew into a complete overburden (SiO2@PDA). Afterward, Pt atomic clusters were anchored on the outer shells of HCSs-4 to construct composite electrocatalysts (Pty/HCSs-4) by a chemical reduction method. Due to the low charge-transfer resistance, the HCSs have a large electrochemical surface area and provide a continuous electron transport pathway, boosting the atom utilization efficiency during hydrogen production and release. The synthesized Pt2.5/HCSs-4 electrocatalysts exhibit excellent HER activity in acidic media, which can be ascribed to the compositional modulation and delicate structural design. Specifically, when the overpotential is 10 A g–1, the overpotential can achieve 92 mV. This work opens a new route to fabricate Pt-based electrocatalysts and brings a new understanding of the formation mechanism of HCSs.
研究领域:
材料科学
·
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2018
·Vol. 29
·期 2
·1806300
·
IF 13.325
Kai Liu,Wei Wang,Penghui Guo,Jinyu Ye,Yuanyuan Wang,Pingting Li,Zixi Lyu,Yongsheng Geng,Maochang Liu,Shuifen Xie
Metal nanostructures with an ultrathin Pt skin and abundant surface defects are attractive for electrocatalytic applications owing to the increased utilization efficiency of Pt atoms and the presence of highly reactive sites. This paper reports a conformal, layer-by-layer deposition of Pt atoms on defective Rh nanowires for the faithful replication of surface defects (i.e., grain boundaries) on the Rh nanowires. The thickness of the Pt shell can be controlled from one monolayer up to 5.3 atomic layers. This series of Rh@Pt n L ( n = 1–5.3) core–sheath nanowires show greatly enhanced activity and durability in catalyzing the ethanol oxidation reaction in an acidic medium. Among others, the Rh @ Pt 3.5L nanowires show the greatest mass activity (809 mA mg −1 Pt ) and specific activity (1.18 mA cm −2 ) after loaded on carbon support, which are 3.7 and 3.4 times those of the commercial Pt/C, respectively. In situ Fourier transform infrared spectroscopy studies indicate an enhanced interaction between the outermost Pt layer and the Rh nanowire can promote C C bond cleavage for complete oxidation of ethanol to CO 2 while depress the dehydrogenation of ethanol to acetic acid. As the Pt shell thickness is increased, the selectivity for the CO 2 pathway decreases while that for acetic acid is increased.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ChemNanoMat
·
2020
·Vol. 6
·期 8
·1191-1199
·
IF 3.384
Huixiang Li,Changhui Liang,Pan Gao,Guangjin Hou,Kairui Liu,Wei Liu,Qike Jiang,Shi Bai,Z. Conrad Zhang
Graphical In stock : Stock solutions of reduced mononuclear M 1 (0) (M=Pt, Au) atoms are prepared from their chloride salt precursors in removable solvent glycol ether/ethanol/H 2 O. Glycol ether and HCl function as strippable shields prevent M 1 (0) atoms from aggregation. The releasable M 1 (0) atoms suit as building-blocks for designable bottom-up material fabrications. Specifically, M 1 (0) atoms are readily transported onto the TiO 2 surface and remain in the reduced mononuclear state. Premade and readily transportable mononuclear zero-valent metal atoms in stock solvents offer the potential capability for bottom-up designable metallic material fabrication. This work demonstrates a potentially universal and practical strategy to prepare weakly shielded mononuclear metal atoms in a volatile solvent, which also constitutes a strippable ligand to the metal atoms. Herein, M 1 (0) (M=Pt, Au) atoms are prepared by reducing H 2 PtCl 6 and HAuCl 4 with ethanol in ethylene glycol diethyl ether (EGDE) under mild temperatures. The diether oxygens of EGDE, H + , and Cl − coordinating to the M 1 (0) atoms, make the M 1 (0) atoms stable in the solvent under low pH. However, the M 1 (0) atoms can be released either by evaporation of HCl and EGDE or through neutralization of the HCl with a base. The premade M 1 (0) atoms can be used as primary building blocks to construct designable materials. To demonstrate a potential application, the M 1 (0) atoms are conveniently transported onto the surface of TiO 2 through impregnation followed by mild heating. The atomic dispersion and reduced state of the metal atoms are well preserved, as verified by HAADF-STEM images, XPS, and DRIFT spectroscopy.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2020
·
IF 5.627
Fuchang Gao,Zuwei Xu,Haibo Zhao
In this paper, flame spray pyrolysis (FSP) is used to synthesize Pt/TiO 2 catalysts with surface-supported isolated Pt atoms through elaborate precursor/solvent formulation and flame temperature history control. It is a pivotal factor to this FSP process that there is a major distinction on saturated vapor pressure between two components (Pt species and Ti species), and thereby they exist as gas phase and particle phase at a certain temperature range, respectively. When the flame is quenched to ambient temperature with cold sheath gas , Pt species of gaseous PtO 2 (being in the vapor phase above 723 K) condense into deposition state on the surface of TiO 2 nanoparticles . Combined with X-ray photoelectron spectroscopy (XPS) analysis and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) detection, we identify that Pt atoms are dispersed and anchored on the catalyst surface . Single-atom Pt dispersed Pt/TiO 2 catalysts can be well achieved by controlling the loading at a very low level, which offers an effective way to maximize the atom economy for surface catalysis of scarce noble metals. In this work, considering that Pt as the best co-catalyst of hydrogen evolution, the FSP-made Pt/TiO 2 catalysts are tested in a photocatalysis water splitting system aiming to a simple and attractive means of renewable hydrogen production . The highest activity presents in 0.1Pt/TiO 2 with 0.1% molar ratio of Pt to Ti, reaching 108.5 times of the benchmark sample from commercial flame-made TiO 2 (P25). The high activity is attributed to the fact that the isolated Pt atom serves as the main active site for photocatalysis hydrogen evolution. Therefore, the performance and cost efficiency of catalysts are greatly improved by the FSP, mainly ascribed to engineering atomically dispersing Pt on the support surface.
研究领域:
材料科学
·
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Materials Chemistry Frontiers
·
2020
·Vol. 4
·期 4
·1158-1163
·
IF 6.788
Zewen Zhuang,Yu Wang,Zheng Chen,Dingsheng Wang,Chen Chen,Qing Peng,Yadong Li
Densely populated metal atomic site catalysts play a key role in practical catalysis applications. Herein, we report an amorphous nanobox with high-density atomic platinum species which are uniformly dispersed into the ZIF-8 skeleton through cation exchange. During the dispersing process, the ZIF-8 core was gradually etched into the hollow structure though the Kirkendall effect, and a great amount substitutions of Pt with Zn breaks the initial long-range ordered ZIF-8 topology into a distorted skeleton which leads to the significantly unsaturated coordination of atomic Pt species. The high-density atomic Pt nanoboxes exhibit excellent performance in direct C–H bond borylation of arenes which are usually catalyzed by homogeneous complexes. Such high-density atomic site heterogeneous catalysts could serve as a bridge to convert from homogeneous to heterogeneous catalysis.
研究领域:
化学
·
材料科学
·
催化反应
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 9
·4911-4919
·
IF 11.301
Xingxing Pan,Shuanglong Lu,Duo Zhang,Ye Zhang,Fang Duan,Han Zhu,Hongwei Gu,Shuao Wang,Mingliang Du
Exploring highly efficient and stable electrocatalysts for the hydrogen evolution reaction (HER) has captured widespread attention. Atomic engineering of material structures paves a powerful pathway to develop advanced electrocatalysts by virtue of precisely modulating the reactivity and maximizing the atomic efficiency, although it still stands as a big challenge. In this work, a new method of multiple molecular level confinement is proposed to in situ incorporate atomic platinum (1.5 wt%) into ultrafine transition metal carbides through electrospinning and pyrolysis. The hybrid catalyst exhibits superior electrocatalytic performance towards the HER in acidic medium in terms of overpotential (38 mV at 10 mA cm−2), Tafel slope (27 mV dec−1), mass activity (3.49 A mg−1) and stability (10 mV decay after 5000 CV cycles). Detailed investigation reveals that the excellent performance is mainly attributed to the electronic modulation of atomic Pt over α-MoC1−x and highly exposed active sites originating from atomic and ultrafine properties. The generality of this method is further demonstrated with a Pt-doped ultrafine WCx catalyst. This work elucidates a facile strategy to design efficient electrocatalysts via atomic nanostructure and composition engineering, shedding light on the exploration and optimization of hybrid catalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Feng Long,Bo Zhang,Xincheng Cao,Xiaolei Zhang,Hanjie Ying,Junming Xu,Chenjie Zhu
Herein, we have achieved successful preparation of atomically dispersed catalytic systems, liquid metal Pt x /Ga catalysts, which eliminate the need for reduction processes. Notably, the 0.5 wt% Pt x /Ga catalyst exhibited exceptional stability in hydrogenation performance, achieving 100 % conversion of stearic acid with an impressive 98.7 % selectivity towards octadecane, especially with unprecedented stability over 19 recycling cycles. X-ray absorption spectra (XPS) and density functional theory (DFT) calculations unequivocally establish that isolated Pt atoms, benefitting from charge transfer from the Ga matrix, synergistically optimize Pt metal atom utilization, thereby efficaciously optimizing the d-band center and augmenting hydrogenation proficiency. Furthermore, isolated Pt configuration's weaker CO adsorption ability effectively mitigates concerns of catalyst poisoning and undesirable agglomeration, thereby engendering superior stability. The stronger adsorption with aldehyde and alcohol intermediates promotes the hydrogenation of stearic acid through hydrodehydration pathway, thereby ensuring a high carbon utilization economy. Overall, our work offers insight into the investigation of hydrogenation conversion of bio-derivatives over atomically dispersed catalytic systems.
研究领域:
催化化学
·
材料科学
·
理论计算化学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2022
·Vol. 24
·期 44
·27515-27523
·
IF 3.945
Yunxiao Zhang,Pengfei Yan,Yannan Zhou,Qun Xu
Impregnating noble metals in metal–organic frameworks (MOFs) for obtaining effective catalysts for the photocatalytic process is of great significance but remains very challenging. Herein, for the first time, atomically dispersed Pt atoms were successfully impregated inside the MOF UiO-66 with the assistance of supercritical carbon dioxide (SC CO2). Our study demonstrated that the SC CO2-directed strategy makes Pt undergo a stable encapsulation inside UiO-66, realizing a stage for the rapid transfer of photogenerated electrons between the components of the composite, hence dramatically increasing the catalytic effect. Further, theoretical calculations demonstrated the experimental characterization of the unique structure. Moreover, the as-prepared hybrid structure of Pt@UiO-66 composites presented an extremely high photocatalytic efficiency for hydrogen evolution under visible-light irradiation. An unusual H2 production rate of 3871.4 μmol h−1 g−1 could be achieved by Pt@UiO-66 under visible-light irradiation. This was nearly 50 times higher than the H2-evolution rate achieved by pure UiO-66 under the full spectrum.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Changchun Sun,Chao Wang,Guangting Han,Yuanming Zhang,Haiguang Zhao
The application of layered molybdenum disulfide (MoS 2 ) in catalytic hydrogen production has attracted great interest, while their catalytic properties are limited by poor electron conductivity and a few catalytically active sites. In this work, we demonstrated a highly active electrocatalyst for large-scale hydrogen production, consisting of two-dimensional (2D) Pt-MoS 2 nanosheets along one-dimensional (1D) cobalt nanoparticle integrated carbon hollow nanofibers (Co@CHNF). The as-prepared Pt-MoS 2 -Co@CHNF had a large specific surface area (44.5 m 2 g −1 ). X-ray photoelectron spectrometer (XPS) and spherical aberration corrected transmission electron microscope (AC-STEM) demonstrated that Pt atomic clusters (Pt ACs) were doped on MoS 2 nanosheets by thermodynamically induced spontaneous interfacial redox between MoS 2 and H₂PtCl₆. The Pt-MoS 2 -Co@CHNF based catalysts exhibited an overpotential as low as 91 mV for 10 mA cm −2 and 258 mV for 200 mA cm −2 in 1 M KOH electrolyte, and there is no significant floating for catalytic active with 14 h continuous operation, which demonstrates its excellent long-term operation durability, significantly superior to the previously reported state-of-the-art Co-based or Mo-based catalysts. In particular, the self-supporting binder-free Pt-MoS 2 -Co@CHNF catalyst-based electrode showed an ultra-high current density of 500 mA cm −2 at a low overpotential of 301 mV, without any decrease after 24 h operation at 500 mA cm −2 in 1 M KOH seawater electrolyte, representing a great potential for large-scale seawater hydrogen production.
研究领域:
材料科学
·
能源科学
✓ 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）