MOLECULES
·
2020
·Vol. 25
·期 9
·2109
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IF 3.267
Changzhou Chen,Peng Liu,Haihong Xia,Minghao Zhou,Jiaping Zhao,Brajendra K. Sharma,Jianchun Jiang
It is of great importance to explore the selective hydrogenolysis of β-O-4 linkages, which account for 45–60% of all linkages in native lignin, to produce valued-added chemicals and fuels from biomass employing UV light as catalyst. TiO2exhibited satisfactory catalytic performances in various photochemical reactions, due to its versatile advantages involving high catalytic activity, low cost and non-toxicity. In this work, 20 wt.% Ni/TiO2and oxidant PCC (Pyridinium chlorochromate) were employed to promote the cleavage of β-O-4 alcohol to obtain high value chemicals under UV irradiation at room temperature. The Ni/TiO2photocatalyst can be magnetically recovered and efficiently reused in the following four consecutive recycling tests in the cleavage of β-O-4 ether bond in lignin. Mechanism studies suggested that the oxidation of β-O-4 alcohol to β-O-4 ketone by oxidant PCC first occurred during the reaction, and was followed by the photocatalysis of the obtained β-O-4 ketone to corresponding acetophenone and phenol derivates. Furthermore, the system was tested on a variety of lignin model substrates containing β-O-4 linkage for the generation of fragmentation products in good to excellent results.Keywords:lignin;β-O-4;photocatalyst;Ni/TiO2;oxidant PCC
研究领域:
化学工程
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 10
·6325-6334
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IF 12.732
Peng Zhou,Shuhua Wang,Guangyao Zhai,Xingshuai Lv,Yuanyuan Liu,Zeyan Wang,Peng Wang,Zhaoke Zheng,Hefeng Cheng,Ying Dai,Baibiao Huang
Ni/TiO2 as a classic system has been widely studied in the traditional catalysis field including the water-gas shift reaction and selective oxidation/hydrogenation. However, in terms of the electrocatalytic hydrogen evolution reaction (HER), there is still a lack of systematic research on the actual synergistic promotion effect on the performance, and the influence of the host material on the electronic interaction between Ni and TiO2 is still unclear. Herein, we synthesized a series of Ni/TiO2 composites with different forms and tested the relevant HER performance. The results show that Ni/TiO2 exhibits much better HER performance than pure Ni and there is one type of electronic interaction between Ni and TiO2 in the composite with different forms, that is, electrons transfer from Ni to TiO2. However, the interaction strength is host dependent, and the composite with Ni as the host displays the strongest interaction, and therefore the best HER performance (46 mV at 10 mA cm−2).
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Catalysts
·
2018
·Vol. 8
·期 5
·182
·
IF 3.465
Feng Li,Jinrong Liang,Wenxi Zhu,Hua Song,Keliang Wang,Cuiqin Li
Ni/TiO2catalysts with different morphologies (granular, sheet, tubular and spherical) were prepared. Hydrogen was generated from ethanol aqueous-phase reforming over Ni/TiO2in a water-ethanol-m-chloronitrobenzene reaction system and directly applied intom-chloronitrobenzene catalytic hydrogenation. Thereby, in-situ liquid-phase hydrogenation ofm-chloronitrobenzene over Ni/TiO2without addition of molecular hydrogen was successful. Compared with granular, sheet and spherical Ni/TiO2, the nanotubular Ni/TiO2prepared from one-step hydrothermal reaction had larger specific surface area, smaller and uniformly-distributed pore sizes and more Lewis acid sites. In-situ liquid-phase hydrogenation ofm-chloronitrobenzene experiments showed the nanotubular Ni/TiO2had the highest catalytic activity, which was ascribed to both catalyst morphology and acid sites. Firstly, the nanotubular structure endowed the catalysts with a nanoscale confinement effect and thereby high catalytic performance. Secondly, the Lewis acid sites not only accelerated water–gas shift reaction, enhancing the ethanol aqueous-phase reforming activity for hydrogen generation, but also promoted the adsorption and hydrogenation of –NO2on the active sites of the catalysts.Keywords:Ni/TiO2;morphology effect;in-situ hydrogenation;aqueous-phase reforming;m-chloronitrobenzene
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
KEY ENGINEERING MATERIALS
·
2012
·
IF 0
Hai Feng Chen,Ting Yan
New nano nickel-doped titanium dioxide composites had been produced by a conducting sol-gel method. The alginate gel was used as a template to prevent the conglomeration of the inorganic materials. In this experiment, nickel nitrate, tetrabutyl titanate and sodium alginate were used as main materials to prepare different amount nickel-doped TiO2 particles. The amount of Ni was studied from 0 to 9 mol.-% (where mol.-% refers to the Ni/TiO2 molar ratio), and the Ni/TiO2 composites were characterized by XRD, FT-IR, TG-DTA, and we carried out doping amount, catalyst amount and illumination time influence on photocatalytic performance of nano Ni/TiO2 composite in aqueous methyl orange. The activity of TiO2 gradually increased with the increasing of doping amount, and there was highest catalytic efficiency when Ni = 9 % mol.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
FUEL
·
2023
·
IF 7.4
Peng Li,Senlin Zhang,Zhourong Xiao,Hui Zhang,Fei Ye,Jianmin Gu,Jidong Wang,Guozhu Li,Desong Wang
Catalytic reduction of CO 2 to high value-added chemicals such as methane is crucial in the development of renewable energy and waste disposal. Photo-thermal CO 2 methanation has been received great attention, because the synergistic effect of photo and thermal lead to efficient CO 2 reduction at low temperature. Herein, we reported the synthesis of Ni nanoparticles (NPs) supported on TiO 2 (Ni-TiO 2 ) derived from MIL-125 (Ti-MOFs) for photo-thermal CO 2 methanation. The nanoparticle sizes and electron densities of metallic Ni, defects and chemical properties, photo-thermal and photo-electric characteristics of the catalysts have been systematically characterized by XRD, TEM, CO 2 /H 2 -TPD, XPS, photoluminescence and photocurrent. For the Ni-TiO 2 , the conversion of CO 2 was 56 % under the full spectrum irradiation (1200 mW/cm 2 ) at 325 °C, which was about 1.8 times of that without light irradiation. The selectivity of methane nearly 99 % with a production rate was 95.7 mmol/(g cat ∙h), which was about 2.7 times of that without light irradiation. Meanwhile, the catalysts showed excellent stability without any activity decay during the four cycles testing (32 h). The main reasons for the high catalytic performance for photo-thermal CO 2 methanation were attributed to the uniform distribution of Ni NPs with synergistic effect of large specific surface area of TiO 2 with abundant moderate strength alkaline sites. In addition, good photo-thermal and photo-electric conversion ability make the catalysts possess more photo-generated charge carriers and reduce its recombination.
研究领域:
化学工程
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 12
·8100-8107
·
IF 3.9
Yu Hua,Xiaomeng Zhang,Fulin Chen,Yuantao Sun,Xinyu Wang,Ziliang Wen,Qinghao Tan,Chenxi Sun,Buhe Bateer
In this study, we utilized a simple calcination method to prepare a Ni/TiO2/C composite, which was synchronously grown from magnetic, semiconductor, and conductive materials. XRD, SEM, Raman, and XPS characterization methods were used to analyze the crystal structure, graphitization degree, morphology size, and valence state of Ni/TiO2/C, and its electromagnetic wave absorption performance was tested. It was revealed that rod-like Ni/TiO2/C had good electromagnetic wave absorption performance at a thickness of 1–5.5 mm; in particular, its reflectance reached −40 dB at 3.5 mm and its absorption bandwidth (reflectivity < −10 dB) reached 4.4 GHz (6.0–10.4 GHz) at a thickness of 4.0 mm. It was thus revealed that its electromagnetic wave absorption rate and absorption bandwidth can be regulated by its thickness. Compared with Ni/TiO2, it was proven that the conductive materials (carbon), magnetic materials (Ni), and semiconductor materials (TiO2) in the rod-like Ni/TiO2/C composite can synergistically absorb electromagnetic wave energy through dielectric and magnetic losses.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of CO2 Utilization
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2021
·
IF 7.132
Zairong Yan,Qinghe Liu,Lixing Liang,Jing Ouyang
Here we report a Ni/TiO 2 loaded on attapulgite (ATP) composite catalyst with fairly good CO 2 conversion performance amd outstanding reusability (up to 80 h re-use circles) at ambient pressure. The composite was prepared by sol-gel method using ATP powder as the matrix to load TiO 2 and Ni nanocrystals in an equivalent impregnation process. Catalytic activity of the newly synthesized catalysts was investigated towards hydrogenation of CO 2 at atmospheric pressure in varied temperature between 200 and 450 °C. And in the reaction process, the flow rate of CO 2 gas was 2.5 mL/min and the concentration ratio of H 2 : CO 2 is always 4. The GHSV was 30,000 h −1 . Among the investigated catalysts, the 8 % Ni-TiO 2 -ATP catalyst showed preferable activity at 450 ℃. Improved activity and reducibility were found when adding 8 % Ni due to the enhanced CO 2 activation compared with the pure TiO 2 or ATP matrix, as well as with the other Ni dosages. These improvements were obtained probably due to its higher surface area than TiO 2 catalyst, more surface hydroxyls, and better dispersion on the ATP matrix.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2022
·
IF 4.889
Jie Liu,Jianhao Cui,Lei Chen,Jingjing Chen,Huidong Zheng,S. Ted Oyama
The conversion of terpinolene epoxide to terpinen-4-ol is a desirable chemical transformation for the production of a valuable intermediate. This paper describes a one-pot, two-step system for the reaction that uses a bifunctional Ni/TiO 2 -SiO 2 catalyst with isomerization and hydrogenation capabilities. The TiO 2 -SiO 2 serves to isomerize the starting epoxide. The Ni component works to hydrogenate the allylic double bond. The tandem system achieves a high 64% yield of terpinen-4-ol. X-ray diffraction analysis showed that TiO 2 -SiO 2 was a mixed binary oxide, and Fourier transform infrared spectroscopy of adsorbed pyridine suggested that acid sites were mainly Lewis acid sites. Electron microscopy showed that the Ni/TiO 2 -SiO 2 catalyst consisted of spherical particles comprising a titanosilicate phase with highly dispersed zero-valent Ni or anatase on the surface. Additionally, there was strong interaction between Ni and the TiO 2 -SiO 2 mixed oxides. Control kinetic experiments demonstrated that the tandem use of the catalysts was more effective than simultaneous operation.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zhongming Wang,Xiaoqian Huang,Yong Jia,Lina Guo,Hong Wang,Wenxin Dai
Photocatalytic hydrogen production from formic acid (FA) is a daunting challenge, yet an essential task for the development of hydrogen energy. In this study, a p-NiO/n-TiO 2 heterojunction incorporating 7-nm metallic Ni was fabricated, which demonstrated a remarkable localized surface plasmon resonance (LSPR) effect. Notably, 5 wt% Ni/TiO 2 exhibited 1271-fold higher photocatalytic activity (2416 μmol⋅g −1 ⋅h −1 ) than TiO 2 alone under light radiation at room temperature. The experimental investigations revealed the excitation of distinct components via irradiation by different light sources. Visible light-driven hydrogen production was predominantly influenced by the LSPR-induced hot electrons and holes effects of Ni. Further, FA molecules simultaneously lost and accepted electrons at the Ni 0 –Ti 3+ and Ni 0 –O 2− sites, respectively, generating a bidirectional electron transfer behavior with “valley-shaped” gas-sensitive responses, which was crucial to boost the activity. Moreover, the photocatalytic activity was mainly attributed to the heterojunction and defects structure under UV light irradiation, and Ti 3+ , V O s, and O 2− as adsorption sites for FA. Thus, the synergistic interplay among different light sources could effectively boost the photocatalytic hydrogen production performance. Significantly, this research reveals that the LSPR effect of metallic Ni can effectively regulate electron transfer behavior and enhance visible light-driven photocatalytic activity.
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
Molecular Catalysis
·
2023
·
IF 4.6
Hua Yang,Zemin An,Yuanjie Xu,Lizhi Wu,Li Tan,Yu Tang
The restructuring of a catalyst under working conditions has been recognized as a critical factor that can significantly impact their performance in recent years. In this study, we investigate the behavior of a highly dispersed Ni supported on TiO 2 (P25) catalyst during the partial oxidation of methane (POM) to produce syngas. Our results reveal a distinct oscillation phenomenon in the catalyst's performance over time. The simultaneous oscillations of rapid deactivation and activation are observed, while the catalyst remains active for continuous POM reaction. Comprehensive characterizations suggest that this deactivation is not caused by traditional deactivation mechanisms with coke formation or Ni sintering. The formation of inactive NiTiO 3 results in catalyst deactivation, which is formed between Ni and TiO 2 support in the reductive atmosphere of POM products under high temperature due to strong metal-support interaction (SMSI). The simultaneous presence of oxidative and reductive atmospheres of the reactants and products in the POM reaction leads to the generation or demise of NiTiO 3 . The dynamic change of the Ni active sites during the in-situ reaction leads to the oscillation of the catalytic activity. This study sheds new light on the importance of SMSI in understanding the behavior of catalysts under working conditions.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2022
·
IF 8.047
Beilei Cui,Hua Wang,Jinyu Han,Qingfeng Ge,Xinli Zhu
The relatively cheap and abundant Ni as a catalyst for hydrodeoxygenation (HDO) of biomass lignin-derived phenolics at 350 °C and atmospheric pressure suffers from unfavorable C-C hydrogenolysis toward CH 4 with a lower direct deoxygenation (DDO) activity. Herein, we demonstrate that the activity and selectively of Ni for HDO of m-cresol can be modified through the differences of strong metal-support interaction (SMSI) on anatase and rutile TiO 2 . Characterizations showed that the presence of SMSI depended strongly on the crystal phase of TiO 2 . The SMSI dominates on Ni/a-TiO 2 after reduction at 350 °C, resulting in Ni particles partially covered by a TiO x overlayer, and this overlayer became sufficiently thick at 650 °C, causing a significant reduction of CO chemisorption. Although the catalyst became selective for DDO to toluene, the overall HDO activity was significantly reduced because of excessive SMSI. In contrast, the Ni/r-TiO 2 catalyst reduced at 350 °C exhibited little SMSI and was active for C-C hydrogenolysis like a bare Ni catalyst. Increasing reduction temperature to 650 °C, the Ni/r-TiO 2 catalyst showed moderate SMSI and became selective to toluene through DDO while completely inhibited CH 4 formation. The toluene and total aromatics yields were 84.8 and 92.2%, respectively, at full conversion. More importantly, the turnover frequency for DDO (2.43 min −1 ) on the Ni/r-TiO 2 catalyst reduced at 650 °C was ∼40 and ∼14 times higher than that of Ni on rutile and anatase, respectively, reduced at 350 °C. This study provides an example of “Goldilocks principle” in catalysis, i.e., the best performing catalyst offers a balanced SMSI!
研究领域:
催化
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化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Songshan Zhu,Shimin Ma,Di Song,Yunzhu Wang,Jichang Lu,Tianhao Ai,Huihui Lu,Sufang He,Yongming Luo
The dynamic relationship of TiO 2 crystal phase and strong metal-support interactions (SMSI) of Ni/TiO 2 catalyst was investigated to reveal the induction period of glycerol steam reforming. Comprehensive investigations confirmed that the SMSI between Ni 0 and anatase TiO 2 was formed by anatase TiO 2 encapsulated Ni 0 after H 2 reduction at 500 °C for the Ni/TiO 2 catalyst calcined at 500 °C (Ni/Ti-500R), which inhibited the contact of Ni 0 active sites with reactants and led to the low hydrogen yield in the initial stage of the reaction. Interestingly, the dynamic conversion of anatase to rutile during the GSR process at 600 °C caused the TiO 2 overlayers on the Ni 0 particles to gradually fade, exposing more Ni 0 sites, resulting in a gradual increase in hydrogen yield to 5.93 mol H2 /mol glycerol . In addition, Ni/Ti-500R with a dynamic SMSI inhibited Ni 0 particles sintering and encapsulated carbon deposition, resulting in relatively better stability (21 h) after induction period. In comparison, the designed Ni/TiO 2 catalyst calcined at 600 °C (Ni/Ti-600R) with rutile TiO 2 as the main component inhibited the formation of the classical SMSI, even after 600 °C H 2 reduction, and no excessive TiO 2 encapsulated Ni 0 particles were observed, so no obvious induction period occurred. This study provides new insights into the relationship of SMSI with crystal phases and the induction period in multiphase catalysis, also a new strategy for designing efficient catalysts.
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
危险品化学品经营许可证（带存储）