APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Qinglei Wu,Chenyang Shen,Chang-jun Liu
Suppressing the excessive hydrogenation capacity of palladium has great significance for selective hydrogenation of acetylene. Herein, an amino acid (histidine or His in abbreviation) modified Pd/SiO 2 catalyst (Pd-His/SiO 2 ) for selective hydrogenation of acetylene was prepared by incipient wetness impregnation, followed by hydrogen reduction at 240 °C. The intense interaction between Pd and histidine greatly affects the structure and properties of Pd-His/SiO 2 . The Pd nanoparticles are highly dispersed on the support with an average diameter of 1.0 nm and positively charged. The use of histidine weakens the adsorption of acetylene and ethylene on the metal. Especially, the adsorption of di-σ-bonded ethylene is significantly impaired on the catalyst, which is beneficial to improve the ethylene selectivity. The conversion of acetylene is up to 100.0 % at 160 °C on Pd-His/SiO 2 while the ethylene selectivity reaches 81.5 %. A 50-hour test at 160 °C confirms the good stability of Pd-His/SiO 2 .
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Changliang Guo,Baogang Wu,Sheng Ye,Jianan Liu,Xianhe Deng,Laiyu Luo,Qi Li,Xudong Xiao,Junxia Wang,Jian Liu,Tian Xia,Baojiang Jiang
The in-situ synthesis method to construct a heterostructure with a tight binding interface can promote the separation and transfer of charges, which is particularly crucial for improving photocatalytic efficiency. Herein, we have successfully synthesized a high-efficiency photoreduction catalyst by in situ growing a layer of flaky nickel chromium layered double hydroxides nanosheets (LDH) on carbon nitride hexagonal tube (CN) in hydrothermal. The tube-flakes like CN-LDH heterostructures have enhanced hydrogen evolution efficiency (14.5 mmol h −1 g −1 ), which is about 4.7 times that of pure CN (2.7 mmol h −1 g −1 ) and much higher than that of LDH (0.06 mmol h −1 g −1 ). We attribute this performance improvement mainly to the close-knit heterostructure formed between LDH and CN. This tight combination strengthens the diffusion of self-charge between the two semiconductors to form a strong built-in electric field and band bending. Under the action of the built-in electric field (BIEF), the photogenerated charge can be efficiently separated and oriented fast transfer, thereby greatly improving the photocatalytic efficiency. This work constructs a tightly connected heterostructure photocatalyst through hydrothermal method , and uses the catalyst to convert high-efficiency solar energy into renewable energy .
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
Functional Materials Letters
·
2021
·
IF 2.17
Lei Wei,Xiaomeng Wang,Ya-Na Yu,Hongyan Liu,Yepei Li,Ya-Ni Zhang
For practical application of sodium borohydride (NaBH 4 ) hydrolysis to generate hydrogen, metallic catalysts with low cost but excellent activity are highly desired. However, it remains a big challenge to further improve the activity of non-noble metal catalysts. In this work, photocatalysis technology was successfully introduced to enhance the catalyst activity for NaBH 4 hydrolysis. By means of conventional impregnation-reduction method, CoB nanocatalyst was evenly deposited on graphitic carbon nitride surface, resulting in a Schottky-type photocatalyst (CoB/CN). As expected, hydrogen generation rate was greatly boosted owing to light irradiation. According to the results of capture experiments, photoexcited electron from g-C 3 N 4 could enrich the electron density of CoB surface, which leads to the improvement of catalyst activity. Additionally, the light irradiation facilitates the remarkable decrease of apparent activation energy. Compared with some reported noble metal catalysts, the CoB/CN presents higher activity, especially under light irradiation.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
Journal of Magnesium and Alloys
·
2022
·
IF 11.813
Shaoyang Shen,Liuzhang Ouyang,Jiangwen Liu,Hui Wang,Xu-Sheng Yang,Min Zhu
It has been well known that doping nano-scale catalysts can significantly improve both the kinetics and reversible hydrogen storage capacity of MgH 2 . However, so far it is still a challenge to directly synthesize ultrafine catalysts (e.g., < 5 nm), mainly because of the complicated chemical reaction processes. Here, a facile one-step high-energy ball milling process is developed to in situ form ultrafine Ni nanoparticles from the nickel acetylacetonate precursor in the MgH 2 matrix. With the combined action of ultrafine metallic Ni and expanded graphite (EG), the formed MgH 2 Ni-EG nanocomposite with the optimized doping amounts of Ni and EG can still release 7.03 wt.% H 2 within 8.5 min at 300 °C after 10 cycles. At a temperature close to room temperature (50 °C), it can also absorb 2.42 wt.% H 2 within 1 h. It can be confirmed from the microstructural characterization analysis that the in situ formed ultrafine metallic Ni is transformed into Mg 2 Ni/Mg 2 NiH 4 in the subsequent hydrogen absorption and desorption cycles. It is calculated that the dehydrogenation activation energy of the MgH 2 Ni-EG nanocomposite is also reduced obviously in comparison with the pure MgH 2 . Our work provides a methodology to significantly improve the hydrogen storage performance of MgH 2 by combining the in situ formed and uniformly dispersed ultrafine metallic catalyst from the precursor and EG.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
ChemCatChem
·
2018
·Vol. 10
·期 15
·3206-3213
·
IF 4.674
Ying-Hua Zhou,Suqin Wang,Zhiyan Zhang,Nicholas Williams,Yong Cheng,Jing Gu
Graphical Layer of darkness : Pd nanoparticles (NPs) are highly dispersed onto the hollow NiCo layered double hydroxide (LDH) derived from ZIF-67 through an in situ reduction method. The nanocomposite exhibits superior catalytic performance for hydrogen generation from ammonia borane in aqueous solution at room temperature. Although ammonia borane (NH 3 BH 3 , AB) has been identified as an excellent hydrogen-storage medium, the development of a highly active catalyst that can function under mild conditions for controllable hydrogen release is still a great challenge. The synergistic effect induced by interactions between metal nanoparticles and a support has been widely applied in thermocatalytic conversion processes. In this work, Pd nanoparticles (NPs) highly dispersed on hollow NiCo layered double hydroxide (LDH) were designed for efficient hydrogen generation from AB at room temperature. During the hydrolytic dehydrogenation of AB, Pd/α-LDH and Pd/β-LDH exhibited catalytic activities with total turnover frequency (TOF) values of 49.5 and 28.1 min −1 with activation energy ( E a ) values of 20.56 and 37.56 kJ mol −1 , respectively, at 298 K; thus, these catalysts outperform most Pd-based catalysts. The improved catalytic effect was attributed to the controllable size and fine distribution of the Pd NPs and the collaborative effect provided by the hydroxide of α-LDH and the intercalated anions (HO − ). This catalysts design principle can be easily transferred to other catalyst research fields for energy-conversion and -storage purposes.
研究领域:
材料科学
·
催化化学
·
能源转换与存储
✓ 已验证
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-9
·
IF 14.7
Liu Qiaoxi,Xu Wenjie,Huang Hao,Shou Hongwei,Low Jingxiang,Dai Yitao,Gong Wanbing,Li Youyou,Duan Delong,Zhang Wenqing,Jiang Yawen,Zhang Guikai,Cao Dengfeng,Wei Kecheng,Long Ran,Chen Shuangming,Song Li,Xiong Yujie
Hydrogen spillover widely occurs in a variety of hydrogen-involved chemical and physical processes. Recently, metal–organic frameworks have been extensively explored for their integration with noble metals toward various hydrogen-related applications, however, the hydrogen spillover in metal/MOF composite structures remains largely elusive given the challenges of collecting direct evidence due to system complexity. Here we show an elaborate strategy of modular signal amplification to decouple the behavior of hydrogen spillover in each functional regime, enabling spectroscopic visualization for interfacial dynamic processes. Remarkably, we successfully depict a full picture for dynamic replenishment of surface hydrogen atoms under interfacial hydrogen spillover by quick-scanning extended X-ray absorption fine structure, in situ surface-enhanced Raman spectroscopy and ab initio molecular dynamics calculation. With interfacial hydrogen spillover, Pd/ZIF-8 catalyst shows unique alkyne semihydrogenation activity and selectivity for alkynes molecules. The methodology demonstrated in this study also provides a basis for further exploration of interfacial species migration.
研究领域:
催化化学
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材料科学
·
表面科学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Wenzheng Chen,Xuezhang Xiao,Jiahuan He,Zhong Dong,Xuancheng Wang,Man Chen,Lixin Chen
Sodium borohydride has attracted much attention because of its high hydrogen density, low hydrolysis temperature and safety. However, most of the current catalysts are expensive and their performances are easily attenuated. Therefore, the development of new catalysts with excellent performances and low cost is the key to its application. In this work, a novel dandelion-like CoMoNi–B/ZIF-67 catalyst with excellent performance was prepared by chemical reduction at room temperature, wherein the CoMoNi–B amorphous alloy was evenly wrapped on the ZIF-67 carrier through liquid phase reduction to form a dandelion-like composite catalyst, of which the “flower bud” ZIF-67 carrier is about 500 nm, and the “crown” flocculent amorphous alloy is about 400 nm. The as-synthesized CoMoNi–B/ZIF-67 has a dandelion-like structure, uniform distribution, large specific surface area, and exhibits an excellent catalytic activity with an apparent activation energy of 35.01 kJ/mol calculated by the Arrhenius equation . Its catalytic hydrolysis rate for sodium borohydride reaches up to 6277 (mL H 2 min/g Co and Ni) at 25 °C. Compared with traditional precious metal catalysts, this novel dandelion-like CoMoNi–B/ZIF-67 catalyst has simple preparation, low cost, and easy availability of raw materials, has great potential application for hydrogen generation in NaBH 4 hydrolysis.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Linglong Yao,Xuanyu Lyu,Jiguang Zhang,Yana Liu,Yunfeng Zhu,Huaijun Lin,Yao Zhang,Liquan Li
Nanostructuring and catalyzing are effective methods for improving the hydrogen storage properties of MgH 2 . In this work, transition-metal-carbides (TiC, ZrC and WC) are introduced into Mg–Ni alloy to enhance its hydrogen storage performance. 5 wt% transition-metal-carbide containing Mg 95 Ni 5 (atomic ratio) nanocomposites are prepared by mechanical milling pretreatment followed by hydriding combustion synthesis and mechanical milling process, and the synergetic enhancement effects of Mg 2 NiH 4 and transition-metal-carbides are investigated systematically. Due to the inductive effect of Mg 2 NiH 4 and charge transfer effect between Mg/MgH 2 and transition-metal-carbides, Mg 95 Ni 5 -5 wt.% transition-metal-carbide samples all exhibit excellent hydrogen storage kinetic at moderate temperature and start to release hydrogen around 216 °C. Among them, 2.5 wt% H 2 (220 °C) and 4.7 wt% H 2 (250 °C) can be released from the Mg 95 Ni 5 -5 wt.% TiC sample within 1800 s. The unique mosaic structure endows the Mg 95 Ni 5 -5 wt.% TiC with excellent structural stability, thus can reach 95% of saturated hydrogen capacity within 120 s even after 10 cycles of de-/hydrogenation at 275 °C. And the probable synergistic enhancement mechanism for hydrogenation and dehydrogenation is proposed.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Hengrui Li,Yuchen Niu,Weiyue Hu,Zihao Tao,Yi Qin,Ruiqing Yao,Wenhong Li,Liuyi Pan,Hedan Yao,Dong Li
The highly selective semi-hydrogenation of acetylene in ethylene-rich streams is essential for polyethylene production. However, environmentally friendly non-precious metal catalysts are often limited by the difficulty of balancing activity and selectivity. This study employed a facile in-situ pyrolysis strategy of MOFs to successfully prepare a Ni/ [email protected] heterojunction catalyst. This catalyst exhibited outstanding performance in acetylene semi-hydrogenation, achieving an acetylene conversion of 96.16 % and ethylene selectivity of 87.22 %. Mechanistic studies revealed that its superior performance originates from highly dispersed H 2 activation sites and a unique interfacial synergistic effect. On the one hand, the strong interfacial interaction formed between Ni and ZnO not only significantly enhances the dispersion and air stability of the active Ni 0 species but also effectively promotes the activation and dissociation of H 2 molecules. On the other hand, the electron reconstruction induced by the Ni/ZnO interface significantly reduces the energy barrier of the rate-determining step promotes the rapid desorbed of the product ethylene, and inhibits excessive hydrogenation. This work provides a novel heterojunction engineering strategy for designing highly efficient, stable, and sustainable non-noble metal selective hydrogenation catalysts.
✓ 已验证
产品关联
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2022
·Vol. 16
·期 12
·1689-1699
·
IF 4.803
Li Wang,Li Wen-Ying,Wang Xing-Bao,Feng Jie
Radicals are important intermediates in direct coal liquefaction. Certain radicals can cause the cleavage of chemical bonds. At high temperatures, radical fragments can be produced by the splitting of large organic molecules, which can break strong chemical bonds through the induction pyrolysis of radicals. The reaction between the formation and annihilation of coal radical fragments and the effect of hydrogen-donor solvents on the radical fragments are discussed in lignite hydrogenolysis. Using the hydroxyl and ether bonds as indicators, the effects of different radicals on the cleavage of chemical bond were investigated employing density functional theory calculations and lignite hydrogenolysis experiments. Results showed that the adjustment of the coal radical fragments could be made by the addition of hydrogen-donor solvents. Results showed that the transition from coal radical fragment to H radical leads to the variation of product distribution. The synergistic mechanism of hydrogen supply and hydrogenolysis of hydrogen-donor solvent was proposed.
研究领域:
化学工程
·
物理化学
·
能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2024
·
IF 11.2
Haoyuan Zheng,Yuxiao Jia,Chen Jin,Hang Che,Chia-TseLee,Guang Liu,Li Wang,Yuyuan Zhao,Shixuan He,Haizhen Liu,Xinhua Wang,Yifeng Yu,Mi Yan
The magnesium based metal hydrogen storage composite system Mg(NH 2 ) 2 -2LiH has a theoretical hydrogen storage capacity of 5.6 wt.% and is a promising hydrogen storage material for vehicles. However, its application is limited due to serious thermodynamic and kinetic barriers. Introducing efficient catalysts is an effective method to improve the hydrogen storage performance of Mg(NH 2 ) 2 -2LiH. This article investigates for the first time the use of nano rare earth oxide CeO 2 (∼44.5 nm) as an efficient modifier, achieving comprehensive regulation of the hydrogen storage performance of Mg(NH 2 ) 2 -2LiH composite system through oxygen vacancy driven catalysis. The modification mechanism of nano CeO 2 is also systematically studied using density functional theory (DFT) calculations and experimental results. Research has shown that the comprehensive hydrogen storage performance of the Mg(NH 2 ) 2 -2LiH-5 wt.% CeO 2 composite system is optimal, with high hydrogen absorption and desorption kinetics and reversible performance. The initial hydrogen absorption and desorption temperatures of the composite system were significantly reduced from 110/130°C to 65/80°C, and the release of by-product ammonia was significantly inhibited. Under the conditions of 170°C/50 min and 180°C/100 min, 4.37 wt.% of hydrogen can be rapidly absorbed and released. After 10 cycles of hydrogen release, the hydrogen cycle retention rate increased from 85% to nearly 100%. Further mechanistic studies have shown that the nano CeO 2− x generated in situ during hydrogen evolution can effectively weaken the Mg–N and N–H bonds of Mg(NH 2 ) 2 , exhibiting good catalytic effects. Meanwhile, oxygen vacancies provide a fast pathway for the diffusion of hydrogen atoms in the composite system. In addition, nano CeO 2− x can effectively inhibit the polycrystalline transformation of the hydrogen evolving product Li 2 MgN 2 H 2 in the system at high temperatures, reducing the difficulty of re-hydrogenation of the system. This study provides an innovative perspective for the efficient modification of magnesium based metal hydrogen storage composite materials using rare earth based catalysts, and also provides a reference for regulating the comprehensive hydrogen storage performance of hydrogen storage materials using rare earth catalysts with oxygen vacancies.
研究领域:
材料科学
·
催化
·
氢气存储
·
纳米技术
✓ 已验证
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-10
·
IF 14.7
Wang Hengjia,Qin Ying,Wu Yu,Qiu Yiwei,Ling Ling,Fang Qie,Wang Canglong,Hu Liuyong,Gu Wenling,Zhu Chengzhou
Hydrogen adsorption and desorption in single-phase catalysts often occur at a single catalytic site based on the traditional hydrogen evolution reaction (HER) pathway, which makes it difficult to break the limitation entailed by the Sabatier principle. Herein, β-Pd hydride metallene (β-PdHene) aerogels are synthesized as advanced HER catalysts. A lattice hydrogen-involved mechanism is reported to separate adsorption and desorption sites, which is thermodynamically favorable compared to the traditional reaction pathway. In situ differential electrochemical mass spectrometry and theoretical calculations reveal that lattice hydrogen as additional active sites directly participate in the HER process. Consequently, β-PdHene aerogels exhibit a low overpotential of only 20 mV at 10 mA cm −2 and remarkable HER stability, which are even comparable to commercial Pt/C. Our work opens an avenue to rationally develop highly active HER catalysts, bypassing the design limitations of catalysts under traditional mechanisms.
研究领域:
材料科学
·
化学工程
·
催化
·
电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）