CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Qinglei Wu,Chenyang Shen,Kaihang Sun,Menghui Liu,Chang-jun Liu
Tuning the hydrogenation activity of Pd is an effective method to achieve selective hydrogenation of acetylene. The previous study shows that Pd has a strong interaction with In 2 O 3 , causing a significant change in the electronic structure of the palladium catalyst. Herein, Pd/In 2 O 3 @SiO 2 was prepared by a deposition-precipitation method for selective hydrogenation of acetylene. After the reduction by flowing hydrogen, Pd-In intermetallic compounds can be formed. The concentration of the formed intermetallic compounds is closely associated with the reduction temperature. The Pd-In intermetallic compounds suppress the hydrogen activation ability of Pd and significantly weaken the adsorption of ethylene. Especially, a weak adsorption of di-σ-bonded ethylene is observed, which facilitates the desorption of ethylene and promotes the ethylene selectivity in the semi-hydrogenation of acetylene. The experimental study confirms that there exists an optimum reduction temperature (250 °C) for the formation of the Pd-In intermetallic compounds, with which ∼ 80 % ethylene selectivity and 100 % acetylene conversion have been achieved at 140 °C.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
Crystals
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2022
·Vol. 12
·期 3
·318
·
IF 2.67
Ze Li,Jie-Ying Jing,Zhi-Qiang Qie,Wen-Ying Li
Jet fuel rich in hydroaromatics and cycloalkanes could be derived from direct coal liquefaction oil via the hydrogenation saturation process. Developing an efficient catalyst to transform naphthalene hydrocarbons to hydroaromatics and cycloalkanes with high selectivity plays a significant role in realizing the above hydrogenation saturation process. In this work, Ni2P/Al2O3catalysts were prepared at different reduction temperatures via the thermal decomposition of hypophosphite. We investigated the influence of reduction temperature and the results showed that reduction temperature had an important impact on the properties of Ni2P/Al2O3catalysts. When the reduction temperature was 400 °C, the Ni2P particle size of the Ni2P/Al2O3catalyst was 3.8 nm and its specific surface area was 170 m2/g. Furthermore, the Ni2P/Al2O3catalyst reduced at 400 °C obtained 98% naphthalene conversion and 98% decalin selectivity. The superior catalytic activity was attributed to the smaller Ni2P particle size, higher specific surface area and suitable acidity, which enhanced the adsorption of naphthalene on Ni2P/Al2O3catalyst.Keywords:nickel phosphide;reduction temperature;naphthalene hydrogenation;thermal decomposition of hypophosphite
研究领域:
催化化学
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能源化工
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DOI
高影响因子
ChemistrySelect
·
2022
·Vol. 7
·期 45
·e202203339
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IF 2.307
Junjie Zhang,Zhourong Xiao,Li Wang,Xiangwen Zhang,Guozhu Li
Graphical The key role of Ni valence state on the catalytic SMR performance of Ni/Al 2 O 3 is reported. Ni 0 /Ni 2+ ratio on Ni/Al 2 O 3 is individually regulated by changing the reduction temperature while maintaining the states of nickel particles and support. A deep understanding is gained on how the Ni valence state of Ni/Al 2 O 3 affects the catalytic SMR performance. Steam methane reforming (SMR) is the most mature technology for hydrogen production in industry, and alumina supported nickel (Ni/Al 2 O 3 ) is the most widely used catalyst. Herein, the key role of Ni valence state on the catalytic SMR performance of Ni/Al 2 O 3 is reported. The ratio of Ni 0 /Ni 2+ on Ni/Al 2 O 3 is individually and effectively tuned by changing the reduction temperature after wet impregnation. Catalytic performance of Ni/Al 2 O 3 is greatly dependent on the surface concentration of Ni 0 and Ni 2+ . The catalyst reduced at 675 °C possesses balanced Ni 0 and Ni 2+ sites and exhibits superior catalytic performance, on which 60 % of methane is stably converted at 600 °C. CH 4 -TPD and CO-TPD profiles demonstrate that appropriate Ni 0 /Ni 2+ ratio can promote the adsorption of CH 4 and inhibit the moderate-strength adsorption of CO, which leads to increased SMR activity and selectivity.
研究领域:
化学工程
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材料科学
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DOI
高影响因子
Materials Today Communications
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2022
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IF 3.662
Miao He,Dengdeng Xie,Lian Yin,Kaili Gong,Keqing Zhou
It is well known that poor thermal conductivity , easy leakage in melting, and low fire safety will hinder the practical application of phase change materials (PCMs) in energy storage. In this work, a series of graphene aerogels with different reduction degrees were obtained by regulating the reaction temperature and then compounded with paraffin wax to form composite PCMs. Satisfactorily, the composite PCMs not only showed a considerably improved shape stability compared to pure paraffin wax, but also an improvement in thermal conductivity from 13.56% to 44.44% with the increase of reduction temperature. Besides, the composite PCMs exhibited promising thermal stability and flame resistance. The peak heat release rate of the composite PCMs decreased by 27.5%, 32.1% and 41.3% respectively as the reduction temperature increased. More importantly, the composite PCMs had outstanding photothermal conversion capability, and the temperature of the composite phase change material could rise from 20 ℃ to 63 ℃ after absorbing light for 4 min. Overall, the increase of the reduction temperature of graphene aerogel has an outstanding contribution to improving the energy storage performance and thermal properties of the composite PCMs.
研究领域:
材料科学
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能源存储
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产品关联
DOI
高影响因子
Catalysis Science & Technology
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2020
·Vol. 11
·期 1
·297-311
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IF 5.721
Xiaoqiang Zhang,Peifang Yan,Bin Zhao,Z. Conrad Zhang
The electronic and structural differences of anatase TiO2 (TiO2-A) and rutile TiO2 (TiO2-R) supported Ni catalysts are studied to understand the distinctively different catalytic pathways in guaiacol hydrodeoxygenation over Ni/TiO2-A and Ni/TiO2-R catalysts. Temperature programmed reduction profiles of NiO/TiO2-A and NiO/TiO2-R reveal two types of metal–support interactions. NiO on TiO2-R requires much higher temperature to reduce than NiO on TiO2-A by hydrogen reduction. Surface TiO2-A is partially reduced together with NiO at low temperature driven by strong interaction between reduced Ni and the reducible TiO2-A surface. In situ X-ray photoelectron spectroscopy (XPS), high resolution TEM (HRTEM), and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy of adsorbed CO reveal two types of reduced Ni species on Ni/TiO2-A: Ni0 particles and atomically dispersed electron-rich Niδ− atoms. While Ni0 particles are formed only at high Ni loadings, they are fully encapsulated by an overlayer of partially reduced TiOx, making the surface of Ni particles totally inaccessible to CO and to reactants. The electron-rich Niδ− atoms are favorably formed at all Ni loadings on the TiO2-A surface and show only linearly adsorbed CO in the DRIFT spectra. Electron transfer from Ti and O on the TiO2-A surface to atomically dispersed Ni is indicated by the observation of dominant electron-rich Niδ− species in conjunction with Ti(4+δ)+ and O(2−δ)− on Ni/TiO2-A following H2 reduction. In contrast, the chemical states of metallic Ni0 and Ti4+ remain unchanged on Ni/TiO2-R after H2 reduction. The atomically dispersed Niδ− species, formed only on the Ni/TiO2-A surface, is proposed as the active site responsible for the selective hydrodeoxygenation of guaiacol to phenolics. In contrast, the metallic Ni0 particles formed on the Ni/TiO2-R surface catalyze the typical catalytic hydrogenation, preferentially saturating the aromatic ring.
研究领域:
化学
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材料科学
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催化反应
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DOI
高影响因子
Processes
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2024
·Vol. 13
·期 1
·15
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IF 2.8
Bo Zhang,Peiyu Yao,Fei Li,Li Pan,Wuwan Xiong,Yang Zhang,Xiang Li
Hydrogen production through the catalytic pyrolysis of low-value organic solid waste offers a promising low-carbon and environmentally friendly pathway. However, the design of efficient hydrogen-producing catalysts remains a significant challenge. Herein, NiO/Al2O3as a catalyst precursor was utilized to investigate the effects of reduction temperature gradients (300–800 °C) on the distribution of three-phase products and the composition of gaseous products during the pyrolysis of waste textiles. Compared to unreduced NiO/Al2O3, increasing the reduction temperature (300–700 °C) led to a gradual decrease in liquid-phase products and a notable increase in gas-phase products, with the latter rising by 10.59% at 700 °C. Most strikingly, hydrogen gas production increased by 6.42% under the same conditions. Multi-characterization analyses, including XRD, TEM, and H2-TPR, revealed significant aggregation of highly dispersed Ni species in NiO/Al2O3at higher reduction temperatures. The emergence of XRD characteristic peaks and the (111) crystal face of metallic Ni (Ni0) became apparent at 700 °C. More importantly, the XPS test inferred that the increasement of hydrogen-rich gas production was ascribed to the appropriate Ni0/Ni2+ratio, and the highest hydrogen yield of 41.50% was achieved as the Ni0/Ni2+ratio reached about 1.57. This work not only provides an effective solution for the consumption of waste textiles, but also converts it into high value-added hydrogen-rich gas.
研究领域:
能源科学
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环境科学
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材料科学
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产品关联
DOI
高影响因子
AICHE JOURNAL
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2024
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IF 3.5
Yan Shao,Bohong Wu,Boya Qiu,Rongsheng Cai,Cui Quan,Ningbo Gao,Feng Zeng,Xiaolei Fan,Huanhao Chen
Synergistic Pd–In 2 O 3 catalysts are promising candidates for producing methanol via CO 2 hydrogenation, and the metal phases in them can be tuned by thermal reduction treatment affecting the catalytic activity significantly. This work presents a comprehensive investigation to gain an insight into the effect of thermal reduction temperature on the variation and interaction of Pd and In 2 O 3 phases supported on CeO 2 (viz., PdIn/CeO 2 ) and their correlations with CO 2 hydrogenation toward methanol synthesis. The findings show that Pd/In-rich PdIn alloys and In 2 O 3 with relatively strong interaction are key phases (by reducing the PdIn/CeO 2 at 300°C) for promoting methanol formation, leading to a high selectivity to methanol at 78.9% and space–time yield (STY) of 3.6 g CH3OH g PdIn −1 h −1 . A further increase in reduction temperature (from 300 to 500°C) promoted the formation of homogenized PdIn intermetallic alloys with significantly poor ability for H 2 dissociation and CO 2 activation, and hence poor methanol yield.
研究领域:
催化化学
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材料科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the American Chemical Society
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2023
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IF 15
Jianyu Han,Jingyi Yang,Zhixin Zhang,Xunzhu Jiang,Wei Liu,Botao Qiao,Junju Mu,Feng Wang
Multicomponent alloy (MA) contains a nearly infinite number of unprecedented active sites through entropy stabilization, which is a desired platform for exploring high-performance catalysts. However, MA catalysts are usually synthesized under severe conditions, which induce support structure collapse and further deteriorate the synergy between MA and support. We propose that a strong metal–support interaction (SMSI) could facilitate the formation of MA by establishing a tunnel of oxygen vacancy for metal atom transport under low reduction temperature (400–600 °C), which exemplifies the holistic design of MA catalysts without deactivating supports. PtPdCoFe MA is readily synthesized on anatase TiO2 with the help of SMSI, which exhibits good catalytic activity and stability for methane combustion. This strategy demonstrates excellent universality on various supports and multicomponent alloy compositions. Our work not only reports a holistic synthesis strategy for MA synthesis by synergizing unique properties of reducible oxides and the mixing entropy of alloy but also offers a new insight that SMSI plays a vigorous role in the formation of alloy NPs on reducible oxides.
研究领域:
催化化学
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材料科学
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产品关联
DOI
PubMed
高影响因子
Journal of Energy Storage
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2023
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IF 9.4
Peng Yuan,Haoran Xu,Zeyu Ning,Gang Xiao
Concentrated solar power coupled with thermochemical energy storage (TCES) has emerged as an effective approach for renewable energy utilization. TCES based on perovskites attracts much attention because of temperature tunability and high flexibility. In this work, the electronic structures are simulated by the density functional theory (DFT) method, revealing the reduction temperatures is related to the formation energy of oxygen vacancy (E vac ). The compounds of Ba 1- x Sr x CoO 3- δ with x = 0–1 are synthesized and investigated by experimental methods. According to the results, Ba content improves the redox capacities and reaction kinetics, while Sr content expands the reaction temperatures and enhances the micro morphologies. In addition, all the samples present a greater reversibility after 150 cycles, because the extended pores are beneficial to the oxygen diffusion. Overall, Ba 0.5 Sr 0.5 CoO 3- δ is suggested as a suitable TCES material with a reaction enthalpy of 202.20 kJ kg −1 . This study provides a design principle of composite perovskites for thermochemical energy storage .
研究领域:
材料科学
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能源工程
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
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2024
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IF 11.2
Guilin Wei,Junhong Luo,Wenwen Yong,Jiangfeng Song,Yan Shi,Xingwen Feng,Ning Liu
Controllable nuclear fusion is a major breakthrough in the future energy field and an important way for mankind to pursue clean and sustainable energy. However, since the fusion reaction raw material tritium is radioactive (β decay, half-life is 12.43 years), the leakage of these hydrogen isotopes under accident conditions will bring the risk of explosion and cause radiation damage to human. Therefore, efficient removal of hydrogen isotopes leaked due to accidents is crucial to the safe operation of nuclear fusion and human health. This study utilizes the metal-support interaction effect to design a series of Pd catalysts for efficient catalytic oxidation of hydrogen isotopes. Using pure silicon zeolite as a carrier, Pd is confined in the channel structure using a ligand-stabilized in situ encapsulation method. The prepared catalyst has nanoscale dispersed metal clusters and has excellent hydrogen isotope catalytic oxidation performance. This study systematically explored the effects of catalyst post-treatment methods, reaction space velocity, and reaction temperature on the hydrogen isotope catalytic oxidation conversion rate. The results show that the catalyst can be fully reduced at 600 °C and can achieve a hydrogen isotope catalytic oxidation conversion rate of greater than 98 % (24,000 mL g –1 h –1 ) at 100 °C. The conversion rate for hydrogen is higher than 96 % under the same space velocity at 50 °C. After 35,360 min (∼24.5 d) of continuous testing and intermittent operation, the catalyst can also maintain a conversion rate of 99 % (100 °C, 24,000 mL g –1 h –1 ). A lower reduction temperature will leave some organic matter, which will coordinate and bond on the Pd clusters and thus affect the catalytic activity. Under the same conditions, the hydrogen conversion rate of the catalyst directly reduced at 400 °C was 14 % lower than that of reduction at 600 °C, which proves the criticality of the reduction temperature. This work demonstrates a systematic study of utilizing the confinement effect of molecular sieve pores to obtain Pd cluster catalysts and applying them to the oxidative removal of hydrogen isotopes. It focuses on exploring the impact of the direct reduction temperature of the catalyst on its performance, which may be useful for providing a certain reference for designing relevant catalysts in engineering applications.
研究领域:
化学工程
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核能科学
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催化材料
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产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
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2017
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IF 2.446
Xiao-yu Sun,Chang Liu,Zheng Chen,Yong-qing Ma
In order to reveal the effects of dopant average valence on the photocatalytic performance, Ta and Rh co-doped Ti 0.96 Ta 0.04−x Rh x O 2 (x = 0, 0.008, 0.016, 0.02, 0.024, 0.032, and 0.04) samples were crystallized at 450 °C and 800 °C, respectively; then the 800 °C crystallized x = 0.02 sample was subsequently reduced in the H 2 /N 2 mixture gases at 600, 700, 800, and 900 °C. Under different processing conditions, Ta remains the valence of +5, while the valence of Rh varies. Rh exhibits Rh 3+ and Rh 4+ in the 450 °C crystallized samples and is completely oxidized to Rh 4+ in the 800 °C crystallized samples. In the reduced samples, Rh exists in the forms of Rh, Rh 3+ and Rh 4+ . The optimal photocatalyst is obtained as the ratio of Rh 3+ /Rh 4+ is 2.11 or the average valence of doped Ta and Rh is closest to the +4 valence of substituted Ti.
研究领域:
材料科学
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化学
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催化
✓ 已验证
产品关联
DOI
高影响因子
FIBERS AND POLYMERS
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2025
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IF 2.3
Sun Simin,Pei Liujun,Hu Qiushuang,Saleem Muhammad Asad,Wang Jiping
Graphene not only provides functional finishing for fabrics, but also influences the original physical and mechanical properties of the fabrics, reducing their wearing properties. This study conducted graphene conductive finishing on acrylic/wool blended knitted fabrics using an oxidation–reduction method. The research focused on analyzing the reduction of graphene, fabric conductivity, thermal comfort, and hand feel of the fabric, while studying the effects of reduction temperature and time on electrical conductivity, thermal comfort, moisture absorption, breathability, and hand feel during the graphene process. The results revealed that a higher degree of graphene reduction led to lower surface resistance and enhanced electrical conductivity in the acrylic/wool blended knitted fabrics. The stability of the fabric structure and mechanical characteristics were also influenced by temperature and time, impacting comfort attributes. The reduction temperature and duration directly influenced the reduction degree of graphene, with the maximum reduction degree and lowest surface resistance observed at 75 °C and 90 min. Importantly, there was no significant degradation in the thermal comfort and tactility of the acrylic/wool blended knitted fabrics.
研究领域:
纺织工程
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材料科学
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化学整理
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智能纺织品
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可穿戴技术
✓ 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）