Journal of the Taiwan Institute of Chemical Engineers
·
2016
·
IF 2.848
Huan Liu,Yi Lin,Zhen Ma
Au/M-P-O (M = Mg, Al, Ca, Fe, Co, Zn, La) catalysts were prepared by loading ca. 1 wt.% gold onto commercial metal phosphate supports by deposition-precipitation with urea (DPU), and tested in CO oxidation. Au/La-P-O showed the highest activity, achieving complete CO conversion at 70 °C. Au/Ca-P-O was the second most active, achieving complete CO conversion at 155 °C. The remaining catalysts were not active below 200 °C. In view of the results, we additionally prepared Au/LaPO 4 nanowires by loading ca. 1 wt.% gold onto LaPO 4 nanowires via DPU. The Au/LaPO 4 nanowires catalyst was even more active, achieving complete CO conversion at 15 °C. The catalysts were characterized by N 2 adsorption-desorption, inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and temperature-programmed desorption of O 2 or CO 2 (O 2 -TPD, CO 2 -TPD). Reasons for the higher activity of Au/LaPO 4 nanowires were discussed.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
ACS Catalysis
·
2021
·
IF 13.084
Dongdong Chen,Huarong Lei,Wuwan Xiong,Ying Li,Xiang Ji,Jia-Yue Yang,Baoxiang Peng,Mingli Fu,Peirong Chen,Daiqi Ye
Phosphorus (P) originating from lubricant oil additives or biofuels is an emerging chemical poison in catalytic systems for automotive exhaust after-treatment. Here, we demonstrate that P-poisoning led to severe deactivation of small-pore Pd-SSZ-13 zeolites (with CHA framework) as passive NOx adsorbers (PNA) and CO oxidation catalysts for cold-start exhaust purification applications. Deactivation mechanisms of P-poisoning were unraveled by comparatively examining the P-free and P-loaded Pd-SSZ-13 zeolites using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR), temperature-programmed reduction by hydrogen (H2-TPR), CO pulse adsorption, temperature-programmed desorption using NH3 as a probe molecule (NH3-TPD), ultraviolet/visible light (UV/vis) spectroscopy, and in situ diffuse relectance infrared Fourier transform spectroscopy (DRIFTS). The loss of isolated Pd sites─namely, [Pd(OH)]+ and Pd2+ (located in the eight- and six-membered rings of CHA framework, respectively)─was revealed to be largely responsible for the deactivation of Pd-SSZ-13 in passive NOx adsorption and catalytic CO oxidation. In situ DRIFTS studies using NO or CO as a probe molecule suggest that [Pd(OH)]+ was more susceptible to P-poisoning than Pd2+. Specifically, P-poisoning led to a migration of [Pd(OH)]+ from cationic exchange sites to the zeolite surface, forming inactive metaphosphate (i.e., [Pd(OH)]+PO3–) and bulk PdOx species at high temperatures. In contrast, P-poisoning of Pd2+ sites proceeded via a sequential transformation to [Pd(OH)]+ first, and then to [Pd(OH)]+PO3– and bulk PdOx. This study provides a comprehensive mechanistic understanding on the deactivation of Pd-SSZ-13 by P-poisoning, and may guide the design of high-performance, phosphorus-resistant Pd-zeolite catalysts for cold-start exhaust after-treatment.
研究领域:
催化材料
·
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2016
·
IF 2.758
Haiyan He,Ping Yang,Jia Li,Ruixia Shi,Ling Chen,Aiyu Zhang,Yuanna Zhu
CeO 2 nanostructures with various morphologies were prepared through controlling preparation conditions via a hydrothermal method without any surfactants and templates. Cerium acetate, cerium chloride and cerium nitrate were used as cerium precursors to investigate the influence of anions on the growth process of CeO 2 nanostructures. The morphology evolution of CeO 2 and Ce(OH) 3 nanostructures indicates that the anions play an important role for the growth kinetics of resulting samples. Cl − and Ac − ions promoted the formation of one dementional (1D) CeO 2 nanostructures such as nanowires, nanorods and nano hexagonal prisms, while the oxidizing anion NO 3 - facilitated the synthesis of CeO 2 nanocubes. The hydrothermal reaction temperature is another key to govern the morphologies of CeO 2 nanostructures. The formation process of the nanostructures was explored and the possible growth mechanism was discussed. The variety of CeO 2 nanostructures represented inequable catalytic performance for CO oxidation . Because of different surface areas and structures, CeO 2 nanowires revealed the best catalysis performance while that of the nanocubes is the worst.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING & TECHNOLOGY
·
2015
·Vol. 38
·期 2
·291-296
·
IF 2.442
Chen Zhou,Yexin Zhang,Lingjun Hu,Hongfeng Yin,Wei Guo Wang
Mn-doped La 0.8 Sr 0.2 CoO 3 perovskite oxides (La 0.8 Sr 0.2 Co 1– x Mn x O 3 ; x = 0, 0.1, 0.3, 0.5) were synthesized by a modified sol-gel method. The phase-pure oxides were obtained. CoO and carbonates were formed on the surface of La 0.8 Sr 0.2 CoO 3 . With increasing doping content, these impurities were reduced while the stability of the perovskite structure was improved. The valence state of B-site ions and the amount of absorbed oxygen were influenced by Mn doping. The catalytic activity of the perovskite catalysts was investigated for CO oxidation and simultaneous removal of CO, C 3 H 8 , and NO. For CO and NO removal, La 0.8 Sr 0.2 Co 0.9 Mn 0.1 O 3 exhibited the best performance. For C 3 H 8 removal, the reactivity was promoted linearly with the doping content. The structure-activity relationship is also discussed.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2020
·
IF 2.726
Yafei Guo,Guodong Wang,Xi Yao,Bingqian Liu
Several NiO–CuO–CeO 2 catalysts were prepared via different methods and characterized by different techniques. Structure-activity relationships of the catalysts were demonstrated, and the effect of preparation methods on CO oxidation behaviors was illustrated. Catalytic results evidenced that the NiCuCe-CP and NiCuCe-SG catalysts prepared by co-precipitation and sol-gel methods exhibited better CO oxidation activities and kinetic performance, as evidenced by their lower T 50 values (102 °C and 100 °C) and apparent activation energies (48.80 and 59.28 kJ/mol) as well as higher reaction rates (3.84 and 3.45 μmol/g/s). The XRD and HRTEM results suggested that the active species showed uniform dispersion with minimum crystallite size in the desired catalysts. The XRD, XPS , H 2 -TPR and Raman analysis suggested the formation of Ce 1- x Cu x O 2- δ and Ce 1- x Ni x O 2- δ solid solutions, indicating that the co-precipitation and sol-gel methods reinforced the interactions amongst the ternary metal oxides . This would afford the catalysts more oxygen vacancies for boosted CO oxidation activity. The mechanism was then proposed with the dual synergetic effects in solid solutions for facilitated oxygen mobility and the amorphous active metal oxides for promoted CO chemisorption . The desired NiCuCe-CP and NiCuCe-SG catalysts show potential application for CO abatement in closed-loop air revitalization.
研究领域:
催化化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2020
·Vol. 12
·期 27
·14882-14894
·
IF 6.895
Junfang Ding,Liping Li,Ye Wang,Huixia Li,Min Yang,Guangshe Li
Highly dispersed nanoalloys with a tailored metal–oxide interface are pivotal in developing advanced catalysts with superior performance for applications. Herein, a series of highly dispersed Pt/NiFeAl nanoalloys on amorphous supports were successfully fabricated by a topological transformation of layered-double-hydroxide nanosheets. With increasing reduction temperature, samples Pt/NiFeAl-x (x = reduction temperature) showed a progressive transformation from Pt/NiFeAl-LDH to a mixture (Pt, NiFe alloys, FeOy, and NiOy) supported on amorphous Al2O3, which eventually transformed to atomically dispersed PtNiFe alloys supported on amorphous Al2O3. Systematic sample characterization demonstrates that amorphous alumina-supported PtNiFe nanoalloys are merited by excellent redox ability, outstanding O2 activation ability, and moderate CO adsorption strength. When tested as catalysts for CO oxidation, all samples have demonstrated an apparent interfacial effect on catalytic performance, among which Pt/NiFeAl-600 shows a strikingly high CO oxidation activity at low-temperatures coupled with a broader operation temperature window (i.e. CO conversion >99.0%, 100–400 °C). Such a topological transformation strategy has proven applicable for generating atomically dispersed nanoalloys on amorphous supports for catalytic applications.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Small
·
2022
·Vol. 18
·期 51
·2204611
·
IF 15.153
Yi Rao,Yutong Wu,Xueya Dai,Ya-Wen Zhang,Gaowu Qin,Wei Qi,Song Li
Single-atom catalysts (SACs) exhibit distinct catalytic behavior compared with nano-catalysts because of their unique atomic coordination environment without the direct bonding between identical metal centers. How these single atom sites interact with each other and influence the catalytic performance remains unveiled as designing densely populated but stable SACs is still an enormous challenge to date. Here, a fabrication strategy for embedding high areal density single-atom Pt sites via a defect engineering approach is demonstrated. Similar to the synergistic mechanism in binuclear homogeneous catalysts, from both experimental and theoretical results, it is proved that electrons would redistribute between the two oxo-bridged paired Pt sites after hydrogen adsorption on one site, which enables the other Pt site to have high CO oxidation activity at mild-temperature. The dynamic electronic interaction between neighboring Pt sites is found to be distance dependent. These new SACs with abundant Pt-O-Pt paired structures can improve the efficiency of CO chemical purification.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2021
·
IF 3.512
Yida Huang,Youlong Liang,Chaoran Xie,Qingyuan Gui,Jinlei Ma,Hongxian Pan,Zeyu Tian,Lei Qi,Mei Yang
Ce1–xO2:x%Cu2+ nanobelts were bioinspired, designed, and fabricated using commercial filter papers as scaffolds by adding Cu(NO3)2 in the original sol solution of CeO2 nanobelts, which display excellent catalyst properties for CO oxidation and photocatalytic activity for organic dyes. Compared with pure CeO2, CuO belts were synthesized using the same method and the corresponding Ce0.5O2:50%Cu2+ bulk materials were synthesized without filter paper as scaffolds; the synthesized Ce1–xO2:x%Cu2+ nanobelts, especially Ce0.5O2:50%Cu2+ nanobelts, can decrease the reaction temperature of CO to CO2 at 100 °C with the conversion rate of 100%, much lower than the formerly reported kinds of Ce1–xO2:x%Cu2+ catalysts. Meanwhile, the synthesized Ce1–xO2:x%Cu2+ nanobelts also display better photocatalytic activity for organic dyes. All of these results provide useful information for the potential applications of the synthesized Ce1–xO2:x%Cu2+ nanobelts in catalyst fields.
研究领域:
材料科学
·
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TRANSACTIONS OF TIANJIN UNIVERSITY
·
2018
·Vol. 24
·期 6
·547-554
·
IF 0
Fang Chunyu,Zhong Huixian,Wei Ying,Wang Jiaming,Zhang Siran,Zhang Lihong,Liu Yuan
A new scheme for the preparation of highly dispersed precious metal catalysts is proposed in this work. Samples of LaCo 1− x Pt x O 3 /SiO 2 ( x = 0.03, 0.05, 0.07, 0.09, and 0.10) were prepared through a simple method of citrate acid complexation combined with impregnation. In a nanocrystallite of LaCo 1− x Pt x O 3 , ions of lanthanum, cobalt, and platinum are evenly mixed at the atomic level and confined within the nanocrystallite. In the reduction process, platinum ions were reduced and migrated onto the surface of the nanocrystallite, and the platinum should be highly dispersed owing to the even mixing of the platinum ions in the precursor. When x = 0.05 or lower, the highest dispersion of Pt could be achieved. The highly dispersed Pt is stable, because of the strong interaction between Pt atoms and the support. The catalysts were characterized by BET surface area, temperature-programmed reduction, X-ray diffraction, transmission electron microscopy, CO temperature-programmed desorption, and turnover frequency. Compared with general precious metal Pt catalysts, the LaCo 0.95 Pt 0.05 O 3 /SiO 2 catalyst exhibited better activity for CO oxidation, and it maintained stability at a high temperature of 400 °C for 250 h with complete CO conversion.
研究领域:
材料科学
·
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
Colloid and Interface Science Communications
·
2023
·
IF 4.5
Shihui Jiao,Mingyu Shang,Yan Chen,Guangsheng Pang
The in situ anchoring of metal elements on the surface of nanomaterials is a state-of-the-art technology that can significantly enhance the performance of materials. We have successfully fabricated noble metal-ion modified rutile TiO 2 nanobars, which exhibit exceptional catalytic activity in both H 2 generation and CO oxidation. Firstly, we synthesized Ti 3+ self-doped rutile TiO 2-x nanobars by a simple solvothermal method using Zn as a reductant, resulting in highly crystalline structures with a significant proportion of (110) surfaces. The reduced nanobars chemically absorb the noble metal cations with the addition of a solution of a noble metal salt in the absence of light to form in situ noble metal-ion modified catalysts. TiO 2 nanobars with 1 wt% Pt 2+ and Pd 2+ exhibited excellent performance in photocatalytic H 2 generation from water and low temperature CO oxidation. Moreover, the samples modified with low noble metal ions (0.1 wt%) also show effective activity in H 2 generation.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2020
·
IF 12.35
Yang Chen,Yingxin Feng,Lin Li,Jingyue Liu,Xiaoli Pan,Wei Liu,Fenfei Wei,Yitao Cui,Botao Qiao,Xiucheng Sun,Xiaoyu Li,Jian Lin,Sen Lin,Xiaodong Wang,Tao Zhang
Exclusive Pt species supported on inert substrates have not achieved satisfactory performance for cryogenic CO oxidation because of the constraint of the competitive Langmuir–Hinshelwood process in which the strongly adsorbed CO inhibits the activation of O2. Here, we develop a catalyst of Pt nanoparticles on Al2O3 that exhibits extremely high activity with 100% CO conversion at −20 °C and orders of magnitude higher specific rate than current commercial catalysts. Detailed catalyst characterizations reveal the presence of metallic Pt sites and positively charged ones associated with the OH species in Pt/Al2O3. Both experimental data and theoretical calculations suggest that CO adsorbed on Pt(OH) kink sites reacts with OH species covering Pt0 terrace sites to release CO2. Afterward, O2 is facilely activated on terrace sites to regenerate OH. The presence of OH species and the synergy between Pt kink and terrace sites on the Pt species lead to an ultralow reaction barrier for CO oxidation.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
Nanoscale
·
2021
·Vol. 13
·期 14
·6856-6862
·
IF 7.79
Fan Yang,Chunzheng Wu,Hongbo Yu,Shiwei Wang,Tong Li,Bo Yan,Hongfeng Yin
Nanosized Au catalysts suffer from serious sintering problems during synthesis or catalytic reactions at high temperatures. In this work, we integrate dumbbell-shaped Au–Fe3O4 heterostructures into hollow ZrO2 nanocages to make Au–Fe2O3@ZrO2 yolk–shell nanoreactors with high activity as well as ultra-high sintering resistance for high-temperature CO oxidation. The synthesis starts with the fabrication of a (Au–Fe3O4)@SiO2@ZrO2 core–shell nanostructure with a Au–Fe3O4 dumbbell nanoparticle (DB) core and SiO2/ZrO2 double shells, followed by calcination and the selective removal of the inner SiO2 shell with alkaline solution to obtain Au–Fe2O3@ZrO2 nanoreactors. The retained ZrO2 hollow (outer) shells protect the Au NPs from aggregation at temperatures up to 900 °C and show excellent long-term stability. Compared to Au@ZrO2 yolk–shell nanoreactors, Au–Fe2O3@ZrO2 shows improved activity in CO oxidation due to the active Au–Fe2O3 interface. This strategy can be extended to other yolk–shell nanoreactors with various nanocomposites and for different catalytic reactions.
研究领域:
材料科学
·
催化化学
·
纳米技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）