Energy Materials
·
2024
·Vol. 4
·期 6
·N
·
IF 11.8
Zuwei Xu,Ze Zhang,Fuchang Gao,Yuhan Zhu,Haibo Zhao
Catalytic combustion is an effective approach to remove air pollutants from various emission sources. For this purpose, supported noble metal catalysts are preferred in commercial applications due to their outstanding catalytic activity for eliminating CO, hydrocarbon compounds and NOx. In this paper, we employ the flame spray pyrolysis method to prepare a series of Pt-based catalysts with four different supports (TiO2, ZrO2, MgO and ZnO) and variable low Pt loadings for catalytic combustion of CO and CH4. The performance of 0.5 Pt/TiO2 is the best in all samples, in which the T90 temperatures are 107 and 500 °C for 90% conversion of CO and CH4, respectively. To examine its thermal stability, a time-on-stream test at 700 °C for 420 min is carried out, resulting in a decrease of about 5% in the final conversion of CH4. The X-ray diffraction results show that TiO2 support is a mixed phase with a major amount of anatase and a small amount of rutile other than a pure phase of ZrO2, MgO and ZnO. Furthermore, X-ray photoelectron spectroscopy analysis and high-angle annular dark-field scanning transmission electron microscopy observation show that when the Pt loading is low, the Pt species exist as highly dispersed single atoms on the surface of the TiO2 support. As the Pt loading gradually increases, the state of the Pt species transitions from single atoms to Pt clusters, resulting in a decrease in dispersion. Ultimately, the Pt can successfully accumulate on the surface of the TiO2 nanoparticles, providing abundant active sites for efficient catalytic combustion reactions.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
Processes
·
2021
·Vol. 9
·期 2
·230
·
IF 2.847
Peng Peng,Jun Li,Shengpeng Mo,Qi Zhang,Taiming Shen,Qinglin Xie
Carbon monoxide (CO) and hydrocarbons (HCs) generally have competitive adsorption on the active site of noble-metal nano-catalysts, thus developing an effective way to reduce the passivation of competitive reaction with each other is an urgent problem. In this study, we successfully synthesized transition metal-noble metal (Pt-M) alloys via introducing inexpensive metal elements (M = Ni, Co and Cu) into Pt particles and then deposited on alumina support to form Pt-based catalysts. Subsequently, we choose CO and toluene as polluting gases to evaluate the catalytic activities of Pt-M/Al2O3catalysts. Introducing inexpensive metal elements (M = Ni, Co, and Cu) significantly changed the physicochemical properties and catalytic activities of these Pt-based catalysts. It can be found that the Pt-Co/Al2O3catalyst exhibited outstanding catalytic activity for CO and toluene oxidation under mixed gas atmosphere, compared with other Pt-based catalysts, which is due to the higher dispersity, more surface adsorption oxygen, and well redox ability. Surprisingly, H2O could promote the catalytic activities for CO/toluene co-oxidation over the Pt-Co/Al2O3catalyst. Thus, the present synthetic strategy not only opens an avenue towards the synthesis of noble metal-based catalysts, but also provides an excellent tolerance to H2O in the catalytic process.Keywords:bimetallic alloy;Pt-based catalysts;catalytic oxidation;toluene;moisture
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2017
·Vol. 9
·期 17
·5467-5474
·
IF 7.367
Yue Sun,Yunjie Zhou,Cheng Zhu,Lulu Hu,Mumei Han,Aoqi Wang,Hui Huang,Yang Liu,Zhenhui Kang
Highly efficient electrocatalysts remain huge challenges in direct methanol fuel cells (DMFCs). Here, a Pt–Co3O4–CDs/C composite was fabricated as an anode electrocatalyst with low Pt content (12 wt%) by using carbon dots (CDs) and Co3O4 nanoparticles as building blocks. The Pt–Co3O4–CDs/C composite catalyst shows a significantly enhanced electrocatalytic activity (1393.3 mA mg−1 Pt), durability (over 4000 s) and CO-poisoning tolerance. The superior catalytic activity should be attributed to the synergistic effect of CDs, Pt and Co3O4. Furthermore, the Pt–Co3O4–CDs/C catalyst was integrated into a single cell, which exhibits a maximum power density of 45.6 mW cm−2, 1.7 times the cell based on the commercial 20 wt% Pt/C catalyst.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Yajie Dai,Shuxian Di,Yueling Guo,Fanghui Wang,Zhiqian Wang,Hong Zhu
Pt-based alloy catalysts are popular for fuel cell oxygen reduction reactions (ORRs) because of their high activity and low cost. However, during the preparation and reaction processes, metal nanoparticles tend to aggregate, which affects the activity and stability of the catalyst. To address this issue, this work uses Zeolite-type imidazolic acid framework material (ZIF) crystal shells to coat PtCu alloy catalysts, and N-doped nanoporous carbon layers derived from ZIFs are used to protect individual metal nanoparticles . The appropriate thickness of the ZIF-derived carbon protective layer is reported to effectively inhibit the aggregation of metal nanoparticles during high-temperature calcination , improve the utilization rate of Pt atoms and enhance the activity and stability of Pt-based catalyst. N-doping stabilizes the metal nanoparticles by enhancing their interaction with carriers. Electrochemical test results demonstrated that the mass activity of the prepared 3-Co-PtCu/NC is 6.9 times and 4.3 times that of commercial Pt/C and PtCu/C, respectively. Furthermore, the excellent half-wave potential is maintained even after 10,000 cycles. In single-cell test, the performance of 3-Co-PtCu/NC is better than Pt/C. This study provides a strategy for controlling the aggregation and detachment of metal nanoparticles in metal-based catalysts, which is conducive to improving the performance of 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
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Ying Xu,Kang Xue,Minhua Ai,Zehao Han,Chengxiang Shi,Ruijie Gao,Xiangwen Zhang,Ji-Jun Zou,Lun Pan
Dehydrogenation reaction occurs for the hydrogen release process of liquid organic hydrogen carriers (LOHCs), the regenerative cooling of advanced aircraft, etc. But the synergistic effects of Pt active sites are still ambiguous. Herein, a series of Pt-based catalysts with tunable Pt 0 -Pt δ+ sites were fabricated by changing the ratio of highly dispersed defected TiO 2 on MCM-41 (M41) for efficient dehydrogenation of methylcyclohexane (MCH). The characterizations indicate TiO 2 nanoparticles (NPs) are highly dispersed on M41 support, and possess abundant Ti 3+ /oxygen vacancies. The increase of TiO 2 loading amount can enhance the interaction between Pt NPs and TiO 2 , which increases Pt δ+ /Pt 0 ratio gradually. The dehydrogenation test and theoretical results confirm that the synergistic effect of Pt 0 and Pt δ+ sites contributes the optimal dehydrogenation performance, in which Pt 0 promotes the consecutive C–H bond cleavage and Pt δ+ significantly decreases the desorption energy barrier for H 2 and toluene (TOL). Specifically, the MCH conversion (when applied for LOHCs) is ca. 88 % and the selectivity of TOL is over 99.5 % under 1.0Pt/0.5TiO 2 /M41, while the high MCH conversion of 90 % and TOL selectivity of more than 86 % are achieved under 1.0Pt/1.0TiO 2 /M41 (as regenerative cooling for hypersonic vehicle). This work provides the approach of modulating the synergistic active sites to obtain high-performance dehydrogenation catalyst.
研究领域:
催化化学
·
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Zilong Shao,Shunan Zhang,Xiaofang Liu,Hu Luo,Chaojie Huang,Haozhi Zhou,Zhaoxuan Wu,Jiong Li,Hui Wang,Yuhan Sun
Methanol is a suitable raw material for in situ hydrogen generation by steam reforming that enables the safe storage and transportation of hydrogen. Pt-based catalysts have been considered promising and effective for methanol steam reforming but suffer from deactivation by metal sintering. In this study, we developed an efficient K-modified Pt catalyst confined within silicate-1 zeolite with a high activity and unprecedented stability for methanol steam reforming. Owing to the confinement effect, the K-promoted Pt@S-1 catalyst remained stable for more than 50 h. The combination of TPSR-MS and DFT calculations revealed that the Pt-K@S-1 catalyst exhibited a synergistic effect between the Pt 0 and Pt δ+ species. The cleavage of the O–H bond in CH 3 OH was activated over Pt 0 sites to produce HCOOCH 3 , whereas Pt δ+ sites promoted the hydrolysis of HCOOCH 3 to HCOOH and ultimately CO 2 and H 2 , thus suppressing the formation of CO and boosting H 2 production.
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
Molecular Catalysis
·
2023
·
IF 4.6
Yanlin Xu,Zhuoyi Liu,Bin Liu,Bin Dong,Yuan Pan,Yanpeng Li,Yichuan Li,Hailing Guo,Yongming Chai,Chenguang Liu
Transformation of lignin-derived feedstocks into valuable hydrocarbons is of significant importance but still challenging. This work investigates the hydrodeoxygenation (HDO) of lignin compound guaiacol on Pt-based catalysts with improved surface hydrophobicity and metal dispersion for the first time. The efficiency of guaiacol hydrodeoxygenation into hydrocarbons over Nb 2 O 5 -modified Pt-based catalyst reaches 51 %, nearly doubling that over unmodified Pt/γ-Al 2 O 3 catalyst (25 %). On the one hand, Nb 2 O 5 causes the decrease of hydroxyl groups on catalyst, leading to the enhanced hydrophobicity of catalysts, which increases the reaction rate of guaiacol into hydrocarbons on unit of Pt metal sites. On the other hand, Nb 2 O 5 strengthens the metal-support interaction, which minimizes the size of Pt nanoparticles, providing more exposed metal sites, thus leading to a higher hydrocarbons yield on catalyst. However, excess introduction of Nb 2 O 5 leads to partial coverage of Pt metal sites, resulting in decreased yield of hydrocarbons. Furthermore, the routes of guaiacol HDO reaction over modified Pt-based catalysts are investigated. This work further illustrates the influence of catalyst surface properties on the HDO process of lignin compound, and thereby provides a promising approach for adjustment of catalyst surface properties in order to promote water-liberated reactions.
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
CATALYSIS COMMUNICATIONS
·
2017
·
IF 3.33
Fei Chen,Feng Wang,Qing Li,CaiYuan Cao,Xiang Zhang,Hua Ma,Yu Guo
Different catalyst supports, namely: commercial Degussa P25 TiO 2 , anatase TiO 2 (CC), γ-Al 2 O 3 , and lab-synthesized AlOOH were used to prepare Pt-based catalysts for the room temperature formaldehyde oxidation. XRD, BET and XPS were conducted to characterize the bulk structure of support, the oxidation state of surface elements and the ratio of oxygen in hydroxyls to the total surface oxygen, as well as textural properties of catalysts. For the first time, a long-term activity test at 0% relative humidity was conducted to investigate relationships between the activity of the Pt-based catalysts with Pt dispersion and oxidation state and the relative abundance of surface OH groups. Pt/AlOOH showed the best activity, whereas Pt/P25 TiO 2 gave the worst activity. We consider that both the surface hydroxyl groups and the Pt dispersion are indispensable, and both act synergistically. The specific surface area is not the decisive factor for the present reaction.
研究领域:
催化化学
·
环境催化
·
材料化学
·
表面科学
·
大气污染控制
✓ 已验证
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Fuwen Yang,Jie Zhang,Jinwei Chen,Gang Wang,Tong Yu,Junyu Zhao,Qian Li,Zongbo Shi,Runsheng Zhuo,Ruilin Wang
Propane dehydrogenation (PDH) provides a promising way to meet the requirement of propylene supply, but the commonly-used Pt-based catalysts still suffer from unsatisfactory stability and deactivation. Herein, an interfacial regulation strategy is developed to construct the Cu, Pt, and Zn species modified hollow porous silicalite-1 (CuPt/Zn-HPS-1). Owing to the regulation role of Pt, the electron-deficient [ZnOH] + Lewis acid sites accelerated the C-H activation, which was beneficial to achieve the excellent PDH performance. More importantly, the additionally introduced Cu 2+ further modulated the geometric structure and electronic density of Pt, thus effectively improving the anti-sintering ability and alleviating the coke deposition. Benefiting from the interfacial regulation and Lewis active [ZnOH] + sites, the optimal CuPt/Zn-HPS-1 catalyst exhibited an excellent catalytic PDH performance with the initial propane conversion of 30.4 % and propylene selectivity of 99.0 %. The CuPt/Zn-HPS-1 also demonstrated robust recycling stability in reaction-regeneration cycling test with the smaller deactivation rate constant. This work affords a strategy for improving PDH performance in practical industrial application.
研究领域:
化学工程
·
催化科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Yi-Fan Xue,Jie Feng,Jin-Yao Ma,Wen-Ying Li
C–N bond breaking is a difficult but crucial step in the quinoline removal of coal-based liquids. Noble metal catalysts have higher C–N bond breaking activity, but their surface bond breaking mechanism is unclear. Atomic layer deposition creates more metal-oxide sites and generates different active species, which facilitates the mechanism study. For this reason, we used atomic layer deposition to deposit TiO 2 on the catalyst surface and suggested a more complete C–N bond breaking mechanism in this study. The particle size and pore structure of the catalyst did not change significantly after the deposition, and the hydrogen adsorption was reduced when there were too many layers deposited and the surface Pt sites were occupied to a high degree. TiO 2 is extremely susceptible to reduction to Ti 3+ under hydrogen, and can change the nature of the electron density of Pt through oxygen vacancies, creating Ti 3+ -Pt δ− sites that are prone to protonation reactions. That means, the occurrence of these protonation reactions not only easily breaks the C–N bond, but also accelerates the rate of C–N bond cleavage due to the increased H coverage on the surface of the xcTi-PtAl catalysts. And the Ti 3+ -Pt δ− sites in catalyst had a stronger adsorption effect on the nitrogen-containing compounds, which in turn lowered the energy barriers of bond cleavage. It is concluded that protonation is a necessary step before the C–N bond can be broken. The subsequent steps were showed by the DFT calculations that the nitrogen-containing compounds adsorbed on the Ti 3+ -Pt δ− sites undergo β-H fracture after the protonation reaction, with the elimination reaction cleaving the C–N bond. The xcTi-PtAl catalysts by atomic layer deposition of Ti not only improve the C–N bond breaking performance, but also improve bond breaking stability by a factor of four compared to the Pt/Al 2 O 3 catalysts.
研究领域:
催化化学
·
能源化学
·
表面科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Qi Zhao,Geng Zhang,Guangran Xu,Yingjun Li,Baocang Liu,Xia Gong,Dafang Zheng,Jun Zhang,Qin Wang
The promising Pt-based ternary catalyst is crucial for polymer electrolyte membrane fuel cells (PEMFCs) due to improving catalytic activity and durability for both methanol oxidation reaction and oxygen reduction reaction. In this work, a facile strategy is used for the synthesis ternary RuMPt (M = Fe, Co, Ni, and Cu) nanodendrities catalysts. The ternary RuMPt alloys exhibit enhanced specific and mass activity, positive half-wave potential, and long-term stability, compared with binary Pt-based alloy and the commercial Pt/C catalyst, which is attributed to the high electron density and upshifting of the d-band center for Pt atoms, and synergistic catalytic effects among Pt, M, and Ru atoms by introducing a transition metal. Impressively, the ternary RuCoPt catalyst exhibits superior mass activity (801.59 mA mg −1 ) and positive half-wave potential (0.857 V vs . RHE) towards MOR and ORR, respectively. Thus, the RuMPt nanocomposite is a very promising material to be used as dual electrocatalyst in the application of PEMFCs.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2022
·
IF 3.656
Shudan Deng,Li Ma,Mengyu Gan,Fei Xie,Wei Zhao,Wang Zhan,Wenzhuo Li
Facile constructing novel and stable carrier of Pt-based catalyst for excellent methanol electrochemical is profitable. To this end, a clean and simple synthetic route is used to synthesize Pt supported by bimetallic nitride Co 3 Mo 3 N catalysts (Pt/Co–Co 3 Mo 3 N/PC). On the one hand, thanks to the intensive interaction between Co 3 Mo 3 N and Pt NPs and the ability of Co 3 Mo 3 N itself to provide adsorption OH by decomposing water; on the other hand, P-doped carbon brings an increase in defect sites for better anchoring of Pt NPs, the catalyst Pt/Co–Co 3 Mo 3 N/PC possesses excellent improved catalytic performance for methanol electrooxidation , in which the mass activity is 910 mA‧mg −1 Pt , which is about 2.1 times that of Pt/C-JM. Additionally, the specific activity, anti-CO poisoning capability, and long-term stability of the catalyst are far outstanding to those of Pt/C-JM. The experimental approach in this paper also provides ideas for the commercial application of Pt-based catalysts.
研究领域:
材料科学
·
电化学
·
催化领域
✓ 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）