Catalysts
·
2024
·Vol. 14
·期 11
·827
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IF 3.8
Yumeng Song,Ping Chen,Hui Lou,Xiaoming Zheng,Xiangen Song
In this work, the highly efficient hydrogenation of guaiacol catalyzed by ruthenium supported on Al2O3-TiO2(Ru/Al2Ti1) at very mild conditions was carried out. At temperatures as low as 25 °C and 2 MPa H2, about 60% of guaiacol could be converted to 2-methoxycyclohexanol (MCH) with a selectivity as high as 94% on the Ru/Al2Ti1catalyst with an appropriate hydrogen pressure. At temperatures above 50 °C, almost all of the guaiacol could be converted with the catalyst of Ru/Al2Ti1, mainly into hydrogenated products such as MCH. The surprisingly efficient hydrogenation of guaiacol at low temperatures was most likely due to the ability of Ru particles loaded on the specific complex metal oxide carriers, particularly the reduction of the edge effect of Ru, to activate phenyl and hydrogen and reduce the competition of the dimethoxy process. These findings about the high activity of the Ru/Al2Ti1catalyst at nearly room temperature may be helpful to upgrading the industrial process of the pyrolysis bio-oils.
研究领域:
催化化学
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可再生能源
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工业化学
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2021
·Vol. 14
·期 2
·e202101528
·
IF 5.686
Xue Sun,Fang Li,Zhimiao Wang,Hualiang An,Wei Xue,Yanji Wang
Graphical Nanocatalysis : Highly uniformly dispersed AgPd alloy nanoparticles were anchored on a porous TiO 2 carrier, obtained by calcining precursor and template MIL-125(Ti), and used for FA dehydrogenation, achieving excellent catalytic activity. At 60 °C, the total TOF value of Ag 2 Pd 8 /TiO 2 -M-450-catalyzed FA dehydrogenation was 2579 h −1 . TiO 2 with a disc-like morphology was prepared by direct pyrolysis of a titanium metal–organic framework [MIL-125(Ti)] in air. Highly dispersed bimetallic AgPd nanoparticles were then anchored on TiO 2 and their catalytic performance in the dehydrogenation of formic acid was systematically investigated. The Ag/Pd ratio had a significant effect on the catalyst activity, with Ag 2 Pd 8 /TiO 2 exhibiting the highest total turnover frequency value of 2579 h −1 at 60 °C under an ambient atmosphere. This excellent performance was attributed to the low-crystallinity anatase phase structure and large specific surface area of the TiO 2 carrier, the alloying effect of the AgPd nanoparticles, and abundant electron transfer between the carrier and metal alloy nanoparticles.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
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2021
·
IF 5.062
Jing Zhao,Hucheng Zhang,Haiyan Wang,Jianji Wang
A highly attractive aim is to turn CO 2 into useful chemicals selectively and efficiently, but it still retains great challenging to understand the relations between catalytic performances and interface properties. Here, we report an alternative solution to relate the catalytic activity with the strengths of Lewis acids and bases on the Pd-CoO x interfaces. CoO∙TiO 2 /TiO 2 and CoO x /TiO 2 possess the wide spectrum of Lewis acid/base centres, and give the low selectivity and conversion. The introduction of Pd can focus them on the intrinsic centres, and makes Pd-CoO∙TiO 2 /TiO 2 and Pd-CoO x /TiO 2 represent the ideal catalysis. With temperature-programmed desorptions of CO 2 , CO and NH 3 , it is evidenced that the catalytic hydrogenations of CO 2 to CO, CH 4 and CH 3 OH depend on the cooperation of the Lewis acidic/alkaline centres on the interfaces. The studies provide guidelines for rational design and synthesis of heterogeneous catalysts including but not limited to CO 2 hydrogenation.
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
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Jiapeng Zhang,Jiang Li,Lijing Yang,Ran Li,Fengming Zhang,Hua Dong
Hydrolysis of ammonia borane provides a reliable pathway for hydrogen production , while suitable catalysts are indispensable to make the hydrolysis reaction reach a considerable rate. In the present work, a series of TiO 2 -supported RuCo catalysts have been fabricated by coprecipitation and subsequent reduction of Ru 3+ and Co 2+ on the surface of TiO 2 nanoparticles . Transmission electron microscopy and elemental mapping have verified the good distribution of metal species in the catalysts. The fabricated catalysts have shown excellent performance for catalyzing ammonia borane hydrolysis, especially in alkaline solutions with 0.5 M NaOH. For Ru 1 Co 9 /TiO 2 in which Ru/Co molar ratio is 1:9, the active energy of catalyzed ammonia borane hydrolysis is 33.25 kJ/mol, and a turnover frequency based on Ru as high as 1408 mol H2 /(mol Ru ·min) is obtained at 25 °C. Moreover, when different types of TiO 2 substrates are used, anatase TiO 2 -supported catalysts show better catalytic activity than their counterparts with rutile TiO 2 as substrate or mixture of anatase and rutile TiO 2 as substrate.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2024
·
IF 11.3
Chenfan Gong,Hao Wang,Jian Zhang,Chengguang Yang,Xianni Bu,Haiyan Yang,Jiong Li,Peng Gao
Hydrogenation of CO2 to ethanol is an efficient process for the utilization of CO2 along with the production of value-added chemicals. However, CO2 hydrogenation to ethanol is a complicated reaction, requiring the catalyst to activate CO2 efficiently and accurately regulate the C–C coupling to achieve a high ethanol selectivity simultaneously. Herein, we report the synthesis of RhFeOx catalysts supported on TiO2 with different crystal phase compositions (anatase, rutile, and P25), which were applied for the selective CO2 hydrogenation to ethanol. The RhFeOx/P25 catalyst presented a high dispersion of Rh nanoparticles on the P25 support with abundant Rh0–Rhδ+–OV–Ti3+ (OV: oxygen vacancy) interfacial sites over the anatase/rutile junction. The optimized RhFeOx/P25 catalyst exhibited a high ethanol space–time yield of 18.7 mmol gcat–1 h–1 and a high Rh turnover frequency of 544.8 h–1 with 90.5% ethanol selectivity. An in-depth investigation via various ex situ and in situ characterizations as well as H2/D2 exchange and C2H4 pulse hydrogenation experiments demonstrated that the Rh0–Rhδ+–Ov–Ti3+ interfacial sites played a crucial role in the conversion of CO2 to ethanol. The surface Rh0 sites facilitated the CO2 activation and hydrogenation, while the Rh0–Rhδ+–Ov–Ti3+ interfacial sites boosted the C–C coupling to produce ethanol. The high-performance RhFeOx/P25 catalyst also provides an attractive route for highly efficient ethanol synthesis via CO2 hydrogenation.
研究领域:
催化化学
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环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Wenqing Xu,Yixi Wang,Hong He,Jun Yang,Yang Yang,Jinzhu Ma,Chaoqun Li,Tingyu Zhu
High–performance catalysts are extremely required for controlling NH 3 emission via selective catalytic oxidation (SCO), and the anchoring structural feature of active sites is a key prerequisite for developing them. This study confirms the importance of hydroxyl groups on vacancy–deficient reducible oxides as active groups. On the one hand, spontaneous atomic dispersion of active metal Ir is promoted by the abundant terminal hydroxyl groups. On the other hand, Ir cations anchor on the TiO 2 surface through exchange with H + in Ti–OH groups, and thus occupy the Brönsted acid sites. The adsorption strength of NH 3 is another key factor affecting the reaction rate–determining step, namely NH 3 dehydrogenation , which occurs at a faster rate in the coordinated L–NH 3 rather than the ionic B–NH 4 + . Meanwhile, the coordinated L–NH 3 significantly avoids the competitive adsorption of water vapor in the NH 3 –SCO reaction by reducing the number of hydrogen bonding. The TOF of preferred 0.8Ir/TiO 2 sample is significantly higher than 0.2Ir/TiO 2 sample, although Ir is almost always atomic dispersed. Finally, NH 3 conversion is 85% in a wet circumstance (5% H 2 O) at 240 °C (GHSV = 85 000 h –1 ), with a N 2 selectivity of up to 65% on 0.8Ir/TiO 2 sample.
研究领域:
催化化学
·
环境科学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Qijun Pei,Teng He,Yang Yu,Zijun Jing,Jianping Guo,Lin Liu,Zhitao Xiong,Ping Chen
The strong metal–support interaction (SMSI) is of significant importance to heterogeneous catalysis. The electronic modification and encapsulation of active metals by reducible supports are the intrinsic properties of the SMSI, where the latter would decrease or even cease the catalytic activity of transition metals. Here, we demonstrate for the first time that alkalies are the functional additives that can effectively manipulate the SMSI for better hydrogenation catalysis. Specifically, both thermodynamic analyses and experimental results show that the addition of alkalies to the Ru/TiO2 catalyst could form a titanate top layer that effectively hampers the migration of TiO2–x to the surface of Ru nanoparticles. In the meantime, a substantially enhanced reduction of the support is achieved, leading to an even stronger electron donation from the support to Ru. The alkali-modified Ru/TiO2 exhibits superior low-temperature catalytic activity in the hydrogenation of aromatics, which is ca. an order of magnitude higher than that of the commercial Ru/Al2O3 catalyst and is in clear contrast to that of the neat Ru/TiO2 catalyst that shows negligible activity due to the severe encapsulation of Ru by TiO2–x.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Junfei Chen,Zhihao Yu,Jinwei Wu,Zhao-Bin Ding,Lin Lang,Lining Fang,Xiuli Yin,Zebao Rui
Selective catalytic oxidation of ammonia (NH 3 -SCO) is considered an efficient and environmentally friendly technology to remove trace ammonia pollutants. The Cu-based and Ag-based catalysts have been taken as among the most promising choices for NH 3 -SCO. However, the insufficient NH 3 catalytic activity of Cu-based catalysts and poor N 2 selectivity of Ag-based catalysts restrict their commercial applications. Herein, we report a facile stepwise induced loading method to obtain anatase titania-supported Cu-Ag composite catalysts with well Cu-Ag nanoparticles dispersion and interaction. The enhanced dispersion of Cu-Ag nanoparticles promotes their interaction with TiO 2 support, improves the stability and reducibility of active sites, and finally leads to appropriate chemical states and synergy of the Cu-Ag complex active sites for improving NH 3 conversion and N 2 selectivity. The as-designed CuO x /AgO y /TiO 2 shows outstanding NH 3 -SCO low-temperature catalytic performance with a (>)99 % NH 3 conversion and 83 % N 2 selectivity under 12000 mL g -1 h −1 at 175 °C as well as satisfied long-term stability.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
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