- Nano Express
- Open Access
Synthesis and CO Oxidation Activity of 1D Mixed Binary Oxide CeO2-LaO x Supported Gold Catalysts
© The Author(s). 2017
- Received: 21 August 2017
- Accepted: 24 October 2017
- Published: 2 November 2017
One-dimensional (1D) Ce-La nanorods with different La contents (Ce and La in the molar ratio of 1:0, 3:1, 1:1, 1:3, and 0:1) were synthesized by hydrothermal process. Au/Ce-La nanorod catalysts were obtained by a modified deposition-precipitation method. The samples were characterized by N2 adsorption-desorption (BET), ICP, X-ray diffraction (XRD), SEM, TEM, EDX, X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), and temperature-programmed reduction (H2-TPR). It revealed that La existed as LaO x in the 1D nanorods. The catalysis results demonstrated that the mixed binary Ce-La nanorod oxides could be a good support for gold catalysts. The contents of La had an important influence on the catalytic performance of Au/Ce-La nanorod catalysts. Among the catalysts, when the Ce/La molar ratio was 3:1, the 1.0%Au/Ce0.75-La0.25 nanorods pretreated at 300 °C showed the best activity among the catalysts for CO oxidation, which could convert CO completely at 30 °C. The catalysts also performed high temperature resistance and good stability for CO oxidation at the reaction temperatures of 40, 70, and 200 °C.
- CO oxidation
As a very harmful gas, CO can strongly binds to the iron atom in blood hemoglobin preventing the release of oxygen. So, its presence indoors can even cause the death of human beings and animals in the short time. It has become an increasingly severe problem on air pollution. Catalytic CO oxidation has been one of the most effective solutions for CO removal to solve such serious environmental problem [1–8]. It has also received a great deal attention recently by the scientific community in the fields of the pollution control devices for vehicle exhaust purification, indoor air cleaning, and low-temperature CO sensors [6–10]. In many cases, the precious Au dispersed on specific metal oxides with high oxygen storage capacity such as CeO2, TiO2, and Fe2O3 are highly effective candidates towards the CO oxidation [11–13]. Over the past decades, studies on the supported gold catalysts for CO oxidation at low temperatures have resulted in unexpected observations. It is generally accepted that the catalytic activities of Au catalysts depend strongly on the nature of Au nanoparticles and properties of the supports, such as the gold particle size, the Au metal-support interaction and the reducibility of the support [14–18].
As one of the most important rare earth oxides, CeO2 has been widely used in three-way catalysts as an efficient catalyst support due to its unique physical and chemical properties [6, 8, 15, 17]. CeO2 has an excellent oxygen storage and release capacity due to the ability to switch Ce4+/Ce3+, which makes CeO2 become an active oxide component of various oxidation catalysts used in diverse redox catalytic reactions [17–32]. Surface areas, mesoporous structures, lattice defects, and synergistic effects with other dopants can all promote the catalytic properties of ceria nanomaterials [3, 22]. To further improve the performance of Au-CeO2 catalysts for CO oxidation reaction, many strategies have been tried, such as preparation methods including deposition-precipitation, coprecipitation, and urea-gelation coprecipitation, which has been used to control and optimize the interaction of the Au-O-Ce structure, as well as the size and shape of ceria [33–35]. Attempts have been also made by the surface modification of support [4, 5, 22, 24, 26, 36–38]. It has been found that the use of binary mixed oxides as support could provide a good solution for the stabilization of gold nanoparticles. Moreover, the promotion by noble or transition metal enhances ceria reducibility and facilitates the formation of surface oxygen vacancies. Meanwhile, doping with transition metal cations has been proved to be an effective method to promote the physicochemical properties of one-dimensional (1D) nanostructured nanomaterials, such as catalytic activity [38–40]. Wang et al.  modified the surface of Au/CeO2 with highly dispersed CoO x and demonstrated excellent catalytic activity in low-temperature CO oxidation. Ma et al.  reported that CaO, NiO, ZnO, Ga2O3, Y2O3, ZrO2, and rare earth additives to gold-titania catalyst are beneficial for CO oxidation, and the doped catalysts could show significant activity at ambient temperature after 500 °C aging. Park et al.  reported that CeO x modified TiO2 support is a good catalyst for water gas shift reaction. There have been lots of studies about mixed metal oxides for CO catalytic oxidation. These doped metal ions are either deposited on the surface of the support in the form of oxide particles or into lattice of the support, which could not form a separate oxide phase. The goal of this research is to prepare 1D binary Ce-La nanorods, which is non-perovskite or solid solution type mixed oxide. That is, in the 1D nanorod structure, the two metal oxides coexist combining the merits of the two compositions to maximize the synergistic effect. Due to potential technological applications, a lot of 1D nanomaterials including nanorods, nanowires, and nanotubes have been extensively investigated during the past years [2, 4, 41, 42]. These 1D nanostructured materials, especially 1D nanorod materials, have been studied as important supports or active components in the field of catalysis, optics, and electrochemistry, such as well-controlled silicon nanowires used in solar cells . It has been found that the properties of 1D structure materials such as catalytic activity are often closely related to their crystal structure and shape. As a consequence, the development of 1D nanorod materials to tailor their electronic and catalytic properties proves to be intriguing and valuable.
Herein, we report a simple solvothermal strategy to prepare a series of mixed Ce-La nanorod composites. In the synthesis process, the LaO x and CeO2 could grow together in one rod. The morphology of the final products was not influenced. The XRD and TEM results show that the La cations have existed in the form of LaO x . It was found that the dopant of LaO x showed a positive effect on the activity of gold-ceria catalysts. Au/Ce0.25-La0.75 nanorods exhibited excellent catalytic activity for CO oxidation.
All chemicals in this paper were of analytical grade, and they were used as received without any purification.
The Ce-La nanorods were synthesized by conventional hydrothermal method. In a typical synthesis, solutions of NaOH (9 mol/L) and Ln(NO3)3 (Ln = Ce, La, 0.8 mol/L) were mixed and maintained vigorous stirring for 30 min at room temperature. The resulting suspension was poured into a Teflon-lined stainless steel autoclave. The autoclave was sealed and kept at 110 °C for 14 h and then air-cooled to room temperature. The resulting products were filtered, washed with deionized water and absolute alcohol, dried at 80 °C for 12 h, and then calcined at 400 °C in air with a heating rate of 5 °C min−1 before supporting gold nanoparticles. The final products with different La contents (Ce and La in the molar ratio of 1:0, 3:1, 1:1, 1:3, and 0:1) were denoted as Ce nanorods, Ce0.75-La0.25 nanorods, Ce0.50-La0.50 nanorods, Ce0.25-La0.75 nanorods, and La nanorods.
A deposition-precipitation process was carried out to prepare Au/Ce-La nanorod catalysts. Briefly, the required amount Ce-La nanorods were dispersed in 100 mL deionized water, and then mixed with a certain amount 0.01 mol/L HAuCl4 solution. As the pH of final HAuCl4 solution was about 7, which was related to the basicity of the support and acidity of HAuCl4, pH of the solution would be not adjusted. The suspension was keeping stirring for 12 h and refluxed at 100 °C for 4 h. After the deposition-precipitation procedure, the precipitate was centrifuged, washed with water to remove Cl− ions, and dried at 80 °C under air for 12 h. The concentrations of gold were expressed as percent by mass content.
Gold loadings of Au/Ce-La nanorod catalysts were determined by inductively coupled plasma-atomic emission spectroscopy (ICP-9000, USA Thermo Jarrell–Ash Corp). The Brunauer–Emmett–Teller (BET) surface areas of Ce-La nanorod samples were measured by nitrogen adsorption at − 196 °C using a Micromeritics Tristar II 3020 apparatus. The XRD study was carried out on a Rigaku D/Max-2500 X-ray diffractometer (Kα λ = 0.154 nm) in the 2θ range of 3–80°. Uv-visible DRS of the catalysts were collected on a UV–vis NIR spectrophotometer (JASCO Corp V–570). TEM observations and energy dispersive X-ray analysis (EDX) were obtained with a JEM-2100 transmission electron microscope operating at 200 kV. SEM data and element mapping images were obtained with a JSM-7500F scanning electron microscope operating at 15 kV. XPS were recorded to identify the chemical composition and the oxidation state of the catalysts on a Kratos Axis Ultra DLD X-ray photoelectron spectrometer using a monochromated Al Kα source operated at 150 W. The binding energies were calibrated using the C 1s peak located at 284.6 eV. Temperature-programmed reduction (H2–TPR) was performed on a PX200 apparatus to measure H2 consumption. Prior to H2-TPR analysis, the samples were pretreated in He flow at 300 °C for 1 h. After cooled to 50 °C, the catalyst was reduced with 10 vol% H2/Ar gas flow by heating up to 900 °C at a rate of 10 °C/min.
Catalytic Activity Test
Characterization of Au/Ce-La Nanorod Catalysts
Gold loading of the Au/Ce-La samples with different supports
Nominal gold loading (%)
Actual gold loading (%)
BET specific surface area of the Ce-La nanorod samples with different La contents
BET surface Area (m2/g)
Average pore size (nm)
Pore volume (cm3/g)
SEM and TEM
EDS results of Ce-La nanorods with different La contents
Effect of La Content
In consideration of the preparation methods, gold loadings, gold particle size and distribution on different Ce-La nanorods supports, XRD, TEM and XPS data showed that all the catalysts should have the same number and type of active Au sites. So this high activity of the Au/Ce0.75-La0.25 nanorods catalysts correlates well with the reducibility data discussed above. H2-TPR results indicated that Au/Ce0.75-La0.25 nanorods has the lowest reducibility temperature and highest reducibility in the region of 50–400 °C, especially in the region of 50–150 °C, which could exactly approach the region of reaction temperature. In the process of reaction, the Ce0.75-La0.25 nanorod support served as oxygen carrier. The reducibility of Ce0.75-La0.25 nanorods could promote the formation of active oxygen. That is to say high reducibility of the catalyst, good activity the catalyst has. Au/Ce0.75-La0.25 nanorod catalyst subsequently has the best activity.
Effect of Gold Content
Effect of Calcination Temperature
Reaction Mechanism Speculate
In summary, a series of mixed Ce-La nanorods with various amounts of La was prepared via a simple hydrothermal reaction at high concentration of NaOH and without surfactant. Gold was loaded by deposition-precipitation. After La doping, the composite could retain the initial rod morphology. As a result, Ce-La nanorods with 25 at.% La maintained the optimal nanorods with the length of 0.6 um and the diameter of 3–5 nm. Gold particles were dispersed well on the support. The reducibility of Ce-La nanorods could be affected significantly by LaO x doping. The deposition of gold had important influence on the reducibility of catalyst. Thus, the CO oxidation activity of Au/Ce-La nanorods was essentially changed in comparison with pure Au/CeO2 and Au/La nanorods. One percent Au/Ce0.75-La0.25 nanorods could convert CO to CO2 completely at 30 °C. Further increase in La content results in decreased activity due to the decrease in reducible oxygen sites. The Au/Ce0.75-La0.25 nanorod catalyst with low gold concentration also showed high activity. With the increase of gold content, there is an increase in the activity. The stability test of 0.3% Au/Ce0.75-La0.25 nanorods indicated that the catalyst not only kept 100% conversion after continuous operation for 10 h under 70 °C but also showed no deactivation after 10 h on stream at 40 °C. As expected, the activity of 0.3% Au/Ce0.75-La0.25 nanorods also retained a 100% CO conversion during 50 h at 200 °C. The results revealed that LaO x as the dopant could grow together with CeO2 in one rod. The 1D binary mixed Ce-La nanorods could be a good support for precious metal group catalysts with low content of gold.
This work was supported by the National Natural Science Foundation of China (nos. 21271110, 21373120, and 21271107) and MOE Innovation Team of China (IRT13022).
HHY, WPH, BLZ, and SMZ had conceived and designed the experiments. HHY performed the experiments. SYZ and HHY synthesized and characterized the reported materials. HHY wrote the manuscript. All authors read and approved the final manuscript.
The authors declare that they have no competing interests.
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- Zheng Y, Li KZ, Wang H, Wang YH, Tian D, Wei YG, Zhu X, Zeng CH, Luo YM (2016) Structure dependence and reaction mechanism of CO oxidation: a model study on macroporous CeO2 and CeO2-ZrO2 catalysts. J Catal 344:365–377View ArticleGoogle Scholar
- JM W, Zeng L, Cheng DG, Chen FQ, Zhan XL, Gong JL (2016) Synthesis of Pd nanoparticles supported on CeO2 nanotubes for CO oxidation at low temperatures. Chin J Catal 37:83–90View ArticleGoogle Scholar
- He HY, Yang P, Li J, Shi RX, Chen L, Zhang AY, Zhu YN (2016) Controllable synthesis, characterization, and CO oxidation activity of CeO2 nanostructures with various morphologies. Ceram Int 42:7810–7818View ArticleGoogle Scholar
- Gao JJ, Jia CM, Zhang LP, Wang HM, Yang YH, Hung SF, Hsu YY, Liu B (2016) Tuning chemical bonding of MnO2 through transition-metal doping for enhanced CO oxidation. J Catal 341:82–90View ArticleGoogle Scholar
- Wang H, Zhu HQ, Qin ZF, Liang FX, Wang GF, Wang JG (2009) Deactivation of a Au/CeO2-Co3O4 catalyst during CO preferential oxidation in H2-rich stream. J Catal 264:154–162View ArticleGoogle Scholar
- Soler L, Casanovas A, Urrich A, Angurell I, Llorca J (2016) CO oxidation and COPrOx over preformed Au nanoparticles supported over nanoshaped CeO2. Appl Catal B 197:47–55View ArticleGoogle Scholar
- Zhang XM, Deng YQ, Tian PF, Shang HH, Xu J, Han YF (2016) Dynamic active sites over binary oxide catalysts: in situ/operando spectroscopic study of low-temperature CO oxidation over MnOx-CeO2 catalysts. Appl Catal B 191:179–191View ArticleGoogle Scholar
- Zhang S, Li XS, Zhu B, Liu JL, Zhu XB, Zhu AM, Jang BWL (2015) Atmospheric-pressure O2 plasma treatment of Au/TiO2 catalysts for CO oxidation. Catal Today 256:142–147View ArticleGoogle Scholar
- Haruta M (1997) Size- and support-dependency in the catalysis of gold. Catal Today 36:153–166View ArticleGoogle Scholar
- Liu XY, Liu MH, Luo YC, Mou CY, Lin SD, Cheng HK, Chen JM, Lee JF, Lin TS (2012) Strong metal-support interactions between gold nanoparticles and ZnO nanorods in CO oxidation. Int J Hydrog Energy 42:19894–19902View ArticleGoogle Scholar
- Clarka PD, Sui R, Dowling NI, Huang M, Lo JMH (2013) Oxidation of CO in the presence of SO2 using gold supported on La2O3/TiO2 nanofibers. Catal Today 207:212–219View ArticleGoogle Scholar
- Reina TR, Ivanova S, Centeno MA, Odriozola JA (2015) Catalytic screening of Au/CeO2-MOx/Al2O3 catalysts (M ¼ La, Ni, Cu, Fe, Cr, Y) in the CO-PrOx reaction. Int J Hydrog Energy 40:1782–1788View ArticleGoogle Scholar
- Ayastuy JL, Gurbani A, Guti errez-Ortiz MA (2016) Effect of calcination temperature on catalytic properties of Au/Fe2O3 catalysts in CO-PROX. Int J Hydrog Energy 41:19546–19555View ArticleGoogle Scholar
- Lee DS, Chen YW (2016) Au/CuO-CeO2 catalyst for preferential oxidation of CO in hydrogen-rich stream: effect of CuO content. Int J Hydrog Energy 41:3605–3612View ArticleGoogle Scholar
- Hernandez JA, Gomez SA, Zepeda TA, Gonzalez JCF, Fuentes GA (2015) Insight into the deactivation of Au/CeO2 catalysts studied by in situ spectroscopy during the CO-PROX reaction. Catalogue 5:4003–4012Google Scholar
- Carabineiro SAC, Bogdanchikova N, Pestryakov A, Tavares PB, Fernandes LSG, Figueiredo JL (2016) Gold nanoparticles supported on magnesium oxide for CO oxidation. Nanoscale Res Lett 6:435View ArticleGoogle Scholar
- Mock SA, Sharp SE, Stoner TR, Radetic MJ, Zell ET, Wang RG (2016) CeO2 nanorods-supported transition metal catalysts for CO oxidation. J Colloid Interface Sci 466:261–267View ArticleGoogle Scholar
- Lin YY, ZL W, Wen JG, Ding KL, Yang XY, Poeppelmeier KR, Marks LD (2015) Adhesion and atomic structures of gold on ceria nanostructures: the role of surface structure and oxidation state of ceria supports. Nano Lett 15:5375–5381View ArticleGoogle Scholar
- He GP, Fan HQ, Ma LT, Wang KG, Liu C, Ding DH, Chen L (2016) Dumbbell-like ZnO nanoparticles-CeO2 nanorods composite by one-pot hydrothermal route and their electrochemical charge storage. Appl Surf Sci 366:129–138View ArticleGoogle Scholar
- Li FY, Li L, Liu XY, Zeng XC, Chen ZF (2016) High-performance Ru1/CeO2 single-atom catalyst for CO oxidation: a computational exploration. Chem Phys Chem 17:3170–3175View ArticleGoogle Scholar
- Cordoba LF, Hernandez AM (2015) Preferential oxidation of CO in excess of hydrogen over Au/CeO2-ZrO2 catalysts. Int J Hydrog Energy 40:16192–16201View ArticleGoogle Scholar
- Sudarsanam P, Hillary B, Amin MH, Abd-Hamid SB, Bhargava SK (2016) Structure-activity relationships of nanoscale MnOx/CeO2 heterostructured catalysts for selective oxidation of amines under eco-friendly conditions. Appl Catal B 185:213–224View ArticleGoogle Scholar
- Piqueras CM, Puccia V, Vega DA, Volpe MA (2016) Selective hydrogenation of cinnamaldehyde in supercritical CO2 over Me-CeO2 (Me = Cu, Pt, Au): insight of the role of Me-Ce interaction. Appl Catal B 185:265–271View ArticleGoogle Scholar
- Reina TR, Ivanova S, Centeno MA, Odriozola JA (2016) The role of Au, Cu & CeO2 and their interactions for an enhanced WGS performance. Appl Catal B 187:98–107View ArticleGoogle Scholar
- Gong X, Liu BC, Zhang G, GR X, Zhao T, Shi DC, Wang Q, Zhang J (2016) A mild and environmentally benign strategy towards hierarchical CeO2/Au nanoparticle assemblies with crystal facet-enhanced catalytic effects for benzyl alcohol aerobic oxidation. CrystEngComm 18:5110–5120View ArticleGoogle Scholar
- Bensaid S, Piumetti M, Novara C, Giorgis F, Chiodoni A, Russo N, Fino D (2016) Catalytic oxidation of CO and soot over Ce-Zr-Pr mixed oxides synthesized in a multi-inlet vortex reactor: effect of structural defects on the catalytic activity. Nanoscale Res Lett 11:494View ArticleGoogle Scholar
- Jardim ED-O, Francés SR, Coloma F, Fernández EVR, Albero JS, Escribano AS (2014) Superior performance of gold supported on doped CeO2 catalysts for the preferential CO oxidation (PROX). Appl Catal A 487:119–129View ArticleGoogle Scholar
- López JM, Arenal R, Puértolas B, Mayoral Á, Taylor SH, Solsona B, García T (2014) Au deposited on CeO2 prepared by a nanocasting route: a high activity catalyst for CO oxidation. Catalogue 317:167–175View ArticleGoogle Scholar
- Moemen AA, Mageed AMA, Bansmann J, Wojtan MP, Behm RJ, Kučerová G (2016) Deactivation of Au/CeO2 catalysts during CO oxidation: influence of pretreatment and reaction conditions. Catalogue 341:160–179View ArticleGoogle Scholar
- Good J, Duchesne PN, Zhang P, Koshut W, Zhou M, Jin RC (2017) On the functional role of the cerium oxide support in the Au38(SR)24/CeO2 catalyst for CO oxidation. Catal Today 280:239–245View ArticleGoogle Scholar
- Luengnaruemitchai A, Chawla S, Wanchanthuek R (2014) The catalytic performance of Au/La-CeOx catalyst for PROX reaction in H2 rich stream. Int J Hydrog Energy 39:16953–16963View ArticleGoogle Scholar
- Piumetti M, Andana T, Bensaid S, Russo N, Fino D, Pirone R (2016) Study on the CO oxidation over ceria-based nanocatalysts. Nanoscale Res Lett 11:165View ArticleGoogle Scholar
- Huang XS, Sun H, Wang LC, Liu YM, Fan KN, Cao Y (2009) Morphology effects of nanoscale ceria on the activity of Au/CeO2 catalysts for low-temperature CO oxidation. Appl Catal B 90:224–232View ArticleGoogle Scholar
- Ma TY, Yuan ZY, Cao JL (2010) Hydrangea-Like Meso−/Macroporous ZnO-CeO2 binary oxide materials: synthesis, Photocatalysis and CO oxidation. Eur J Inorg Chem 716-724Google Scholar
- Bao HZ, Chen X, Fang J, Jiang ZQ, Huang WX (2008) Structure-activity relation of Fe2O3-CeO2 composite catalysts in CO oxidation. Catal Lett 125:160–167View ArticleGoogle Scholar
- Tsoncheva T, Ivanova R, Henych J, Velinov N, Kormunda M, Dimitrov M, Paneva D, Slušná M, Mitov I, Štengl V (2016) Iron modified titanium–hafnium binary oxides as catalysts in total oxidation of ethyl acetate. Catal Commun 81:14–19View ArticleGoogle Scholar
- Ma Z, Overbury SH, Dai S (2007) Au/M x O y /TiO2 catalysts for CO oxidation: promotional effect of main-group, transition, and rare-earth metal oxide additives. J Mol Catal A Chem 273:186–197View ArticleGoogle Scholar
- Park JB, Graciani J, Evans J, Stacchiola D, Senanayake SD, Barrio L, Liu P, Sanz JF, Hrbek J, Rodriguez JA (2010) Gold, copper, and platinum nanoparticles dispersed on CeO x /TiO2(110) surfaces: high water-gas shift activity and the nature of the mixed-metal oxide at the nanometer level. J Am Chem Soc 132:356–363View ArticleGoogle Scholar
- Río ED, Hungría AB, Tinoco M, Manzorro R, Cauqui MA, Calvino JJ, Omil JAP (2016) CeO2-modified Au/TiO2 catalysts with outstanding stability under harsh CO oxidation conditions. Appl Catal B 197:86–94View ArticleGoogle Scholar
- Sahu N, Parida KM, Tripathi AK, Kamble VS (2011) Low temperature CO adsorption and oxidation over Au/rare earth-TiO2 nanocatalysts. Appl Catal A 399:110–116View ArticleGoogle Scholar
- Yu P, Wu J, Liu ST, Xiong J, Jagadish C, Wang ZM (2016) Design and fabrication of silicon nanowires towards efficient solar cells. Nano Today 11:704–737View ArticleGoogle Scholar
- Zhu Y, Appenzeller J (2015) On the current drive capability of low dimensional semiconductors: 1D versus 2D. Nanoscale Res Lett 10:425View ArticleGoogle Scholar
- Kang JG, Kim YI, Cho DW, Sohn Y (2015) Synthesis and physicochemical properties of La(OH)3 and La2O3 nanostructures. Mater Sci Semicond Process 40:737–743View ArticleGoogle Scholar
- Yi N, Si R, Saltsburg H, Stephanopoulos MF (2010) Steam reforming of methanol over ceria and gold-ceria nanoshapes. Appl Catal B 95:87–92View ArticleGoogle Scholar
- Tabakova T, Boccuzzi F, Manzoli M, Scobczak JW, Idakiev V, Andreeva D (2006) A comparative study of nanosized IB/ceria catalysts for low-temperature water-gas shift reaction. Appl Catal A 298:127–143View ArticleGoogle Scholar
- Yi N, Si R, Saltburg H, Stephanopoulos MF (2010) Active gold species on cerium oxide nanoshapes for methanol steam reforming and the water gas shift reactions. Energy Environ Sci 3:831–837View ArticleGoogle Scholar
- Majumdar S, Kooser K, Elovaara T, Huhtinen H, Granroth S, Paturi P (2013) Active gold species on cerium oxide nanoshapes for methanol steam reforming and the water gas shift reactions. J Phys Condens Matter 25:376003View ArticleGoogle Scholar
- Pawlak DA, Ito M, Oku M, Shimamura K, Fukuda T (2002) Interpretation of XPS O (1s) in mixed oxides proved on mixed perovskite crystals. J Phys Chem B 106:504–507View ArticleGoogle Scholar
- Reina TR, Ivanova S, Idakiev V, Tabakova T, Centeno MA, Deng QF, Yuan ZY, Odriozola JA (2016) Nanogold mesoporous iron promoted ceria catalysts for total and preferential CO oxidation reactions. J Mol Catal A 414:62–71View ArticleGoogle Scholar
- Kelly KL, Coronado E, Zhao LL, Schatz GC (2003) The optical properties of metal nanoparticles: the influence of size, shape, and dielectric environment. J Phys Chem B 107:668–677View ArticleGoogle Scholar
- Westcott SL, Oldenburg SJ, Lee TR, Halas NJ (1998) Formation and adsorption of clusters of gold nanoparticles onto functionalized silica nanoparticle surfaces. Langmuir 14:5396–5401View ArticleGoogle Scholar
- Carrot G, Valmalette JC, Plummer CJG, Scholz SM, Dutta J, Hofmann H, Hilborn JG (1998) Gold nanoparticle synthesis in graft copolymer micelles. Colloid Polym Sci 276:853–859View ArticleGoogle Scholar
- Link S, El-Sayed MA (1999) Size and temperature dependence of the plasmon absorption of colloidal gold nanoparticles. J Phys Chem B 103:4212–4217View ArticleGoogle Scholar
- Liang S, Broitman E, Wang YN, Cao AM, Veser G (2011) Highly stable, mesoporous mixed lanthanum–cerium oxides with tailored structure and reducibility. J Mater Sci 46:2928–2937View ArticleGoogle Scholar