Screening of Ni-Cu bimetallic catalysts for hydrogen and carbon nanofilaments production via catalytic decomposition of methane

Torres, Daniel; Pinilla, J.L.; Suelves, I.

doi:10.1016/j.apcata.2018.04.011

Cited by 59 publications

(64 citation statements)

References 65 publications

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“…Moreover, while Ni and Cu tend to form fcc structures at ambient conditions, Co and Fe form hexagonal-close-packed (hcp) and body centered cubic (bcc) structures, respectively. In the case of Cu, a substitutional solid solution (Ni x Cu 1-x ) is formed, consistent with the Vegaard's law [51], which was studied for different Cu concentrations in a previous work [38]. Although Cu increased the lattice constant of the Ni x Cu 1-x crystallites (Ni and Ni"), particles were smaller than those of the undoped catalyst.…”

Section: Characterization Of the Catalystssupporting

confidence: 80%

“…Recently we reported a thorough comparative evaluation of Cu-doped Ni/MgO and Ni/Al 2 O 3 catalysts studying the influence of Cu loading, textural promoter, CDM operating mode, temperature, and reactor scale on the carbon nanofilaments yield and their resulting final textural and structural properties [38]. Cu modified the Ni x Cu 1−x alloy crystal lattice and its activity, finding different carbon nanofilament growth mechanisms depending on the textural promoter and the Cu loading used in the preparation of each catalyst.…”

Section: Introductionmentioning

confidence: 99%

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Co-, Cu- and Fe-Doped Ni/Al2O3 Catalysts for the Catalytic Decomposition of Methane into Hydrogen and Carbon Nanofibers

2018

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The catalytic decomposition of methane (CDM) process produces hydrogen in a single stage and avoids CO 2 emission thanks to the formation of high added value carbon nanofilaments as a by-product. In this work, Ni monometallic and Ni-Co, Ni-Cu, and Ni-Fe bimetallic catalysts are tested in the CDM reaction for the obtention of fishbone carbon nanofibers (CNF). Catalysts, in which Al 2 O 3 is used as textural promoter in their formulation, are based on Ni as main active phase for the carbon formation and on Co, Cu, or Fe as dopants in order to obtain alloys with improved catalytic behaviour. Characterization of bimetallic catalysts showed the formation of particles of Ni alloys with a bimodal size distribution. For the doping content studied (5 mol. %), only Cu formed an alloy with a lattice constant high enough to be able to favor the carbon diffusion through the catalytic particle against surface diffusion, resulting in higher carbon formations, longer activity times, and activity at 750 • C; whereas Ni, Ni-Co, and Ni-Fe catalysts were inactive. On the other hand, Fe also improved the undoped catalyst performance presenting a higher carbon formation at 700 • C and the obtention of narrow carbon nanofilaments from active Ni 3 Fe crystallites.

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Section: Characterization Of the Catalystssupporting

confidence: 80%

Section: Introductionmentioning

confidence: 99%

Co-, Cu- and Fe-Doped Ni/Al2O3 Catalysts for the Catalytic Decomposition of Methane into Hydrogen and Carbon Nanofibers

2018

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“…Based on the XRD, TEM, and TPR results, it can be concluded that the formed Ni@La2O3/SiO2 catalyst structure cannot only stabilize small nickel particles and reduce carbon accumulation, but also provides more interface between Ni and La2O3. The latter can promote CO2 activation on oxygen vacant sites and on highly basic nature oxygen sites (lanthana oxycarbonates), which was found to be beneficial for inhibiting carbon deposition and enhancing catalytic performance [42,56]. TEM images of the used catalysts are shown in Figure 10.…”

Section: Characterization Of Used Catalystsmentioning

confidence: 99%

“…Carbon nanofibers and encapsulated graphitic carbon were formed over the used Ni-La 2 O 3 /SiO 2 catalyst. Methane decomposes on the nickel surface forming atomic hydrogen and carbon, the latter diffusing to free surface sites on the nickel particle to form graphitic carbon (the graphitic carbon peak is precisely seen in Figure 9) [55,56]. As shown in Figure 10c, Ni particles in the used Ni-La 2 O 3 /SiO 2 catalyst are in the 10-50 nm range, which is much wider than that found in the used Ni@La 2 O 3 /SiO 2 catalyst.…”

Section: Characterization Of Used Catalystsmentioning

confidence: 99%

Encapsulated Ni@La2O3/SiO2 Catalyst with a One-Pot Method for the Dry Reforming of Methane

Wang

Liu

et al. 2019

Catalysts

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Ni nanoparticles encapsulated within La 2 O 3 porous system (Ni@La 2 O 3 ), the latter supported on SiO 2 (Ni@La 2 O 3 )/SiO 2 ), effectively inhibit carbon deposition for the dry reforming of methane. In this study, Ni@La 2 O 3 /SiO 2 catalyst was prepared using a one-pot colloidal solution combustion method. Catalyst characterization demonstrates that the amorphous La 2 O 3 layer was coated on SiO 2 , and small Ni nanoparticles were encapsulated within the layer of amorphous La 2 O 3 . During 50 h of dry reforming of methane at 700 • C and using a weight hourly space velocity (WHSV) of 120,000 mL g cat −1 h −1 , the CH 4 conversion obtained was maintained at 80%, which is near the equilibrium value, while that of impregnated Ni-La 2 O 3 /SiO 2 catalyst decreased from 63% to 49%. The Ni@La 2 O 3 /SiO 2 catalyst exhibited very good resistance to carbon deposition, and only 1.6 wt% carbon was formed on the Ni@La 2 O 3 /SiO 2 catalyst after 50 h of reaction, far lower than that of 11.5 wt% deposited on the Ni-La 2 O 3 /SiO 2 catalyst. This was mainly attributed to the encapsulated Ni nanoparticles in the amorphous La 2 O 3 layer. In addition, after reaction at 700 • C for 80 h with a high WHSV of 600,000 mL g cat −1 h −1 , the Ni@La 2 O 3 /SiO 2 catalyst exhibited high CH 4 conversion rate, ca. 10.10 mmol g Ni −1 s −1 . These findings outline a simple synthesis method to prepare supported encapsulated Ni within a metal oxide porous structure catalyst for the dry reforming of methane reaction.

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“…Binary nanoparticles (BNPs) are generally nanosized multi-purpose materials which are used in various applications. In fact, application of these materials can increase the activity and stability of the catalyst, reduce the formation of carbon in the reaction of dry methane reforming, increase the strength of super alloys and fix the shape and sizes of the particles [15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Investigating the Effect of CuO/NiO and CuO/CoO Relative Composition on the Reduction Time of (CuO)x-(NiO)(1-x) and (CuO)x-(Co3O4)(1-x) with Methane Gas as the Reducing Agent in the Synthesis of Nano-bimetallic Nix-Cu(1-x) and Cux-Co(1-x)

Ghanbarabadi

Khoshandam

2019

Period. Polytech. Chem. Eng.

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In this paper, the reduction duration of (CuO)x-(NiO)(1-x) and (CuO)x-(Co3O4)(1-x) binary mixtures was studied using thermogravimetric method. The reduction reaction was performed using copper, nickel and cobalt oxides as metal precursors and methane gas as the reducing agent, under atmospheric pressure. The products as well as the raw materials were characterized and analyzed using X-Ray diffraction (XRD) and Energy Dispersive Spectroscopy (EDS). Initially, CoO, NiO and CuO were transformed to Co, Ni and Cu through reduction reactions with 23 Vol.% of methane at 830 °C. Results demonstrated that the reduction times of NiO, CoO and CuO NPs with CH4 at 830 °C were 14, 39 and 47 min, respectively. EDS and XRD analysis indicated that more than 97 % of copper, nickel and cobalt oxides were transformed to copper, nickel and cobalt NPs. The reaction time of (CuO)x-(NiO)(1-x) and (CuO)x-(Co3O4)(1-x) binary mixtures with methane was investigated to evaluate the effect of CuO (x=0, 0.4, 0.6, 1) relative composition. In addition, the reaction time of ternary mixture of (NiO)0.6-(CuO)0.2-(Co3O4)0.2 with methane gas was also studied.

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Screening of Ni-Cu bimetallic catalysts for hydrogen and carbon nanofilaments production via catalytic decomposition of methane

Cited by 59 publications

References 65 publications

Co-, Cu- and Fe-Doped Ni/Al2O3 Catalysts for the Catalytic Decomposition of Methane into Hydrogen and Carbon Nanofibers

Co-, Cu- and Fe-Doped Ni/Al2O3 Catalysts for the Catalytic Decomposition of Methane into Hydrogen and Carbon Nanofibers

Encapsulated Ni@La2O3/SiO2 Catalyst with a One-Pot Method for the Dry Reforming of Methane

Investigating the Effect of CuO/NiO and CuO/CoO Relative Composition on the Reduction Time of (CuO)x-(NiO)(1-x) and (CuO)x-(Co3O4)(1-x) with Methane Gas as the Reducing Agent in the Synthesis of Nano-bimetallic Nix-Cu(1-x) and Cux-Co(1-x)

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