Efficient structured catalysts for ethylene production through the ODE reaction: Ni and Ni–Ce on ceramic foams

A novel γ-alumina-supported Ni-Ce-Zr catalyst with cellular structure was developed for oxidative dehydrogenation of ethane (ODHE). First, powdered samples were synthesized to study the effect of both the total metal content and the Ce/Zr ratio on the physicochemical properties and performance of these catalysts. All synthesized powdered samples were highly active and selective for ODHE with a maximum ethylene productivity of 6.94 µmol ethylene g act cat −1 s −1 . According to the results, cerium addition increased the most reducible nickel species population, which would benefit ethane conversion, whereas zirconium incorporation would enhance ethylene selectivity through the generation of higher amounts of the least reducible nickel species. Therefore, the modification of active site properties by addition of both promoters synergistically increases the productivity of the Ni-based catalysts. The most efficient formulation, in terms of ethylene productivity per active phase amount, contained 15 wt% of the mixed oxide with Ni 0.85 Ce 0.075 Zr 0.075 composition. This formulation was selected to synthesize a Ni-Ce-Zr/Al 2 O 3 structured body by deposition of the active phase onto a homemade γ-alumina monolith. The structured support was manufactured by extrusion of boehmite-containing dough. The main properties of the Ni 0.85 Ce 0.075 Zr 0.075 powder were successfully preserved after the shaping procedure. In addition, the catalytic performance of the monolithic sample was comparable in terms of ethylene productivity to that of the powdered counterpart.

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“…In all cases, a promoter/nickel atomic ratio (Ce+Zr)/Ni was equal to 0.17, as determined in previous studies for NiCe/γ-Al2O3 [9,16].…”

Section: Methodsmentioning

confidence: 75%

Novel Ni-Ce-Zr/Al2O3 Cellular Structure for the Oxidative Dehydrogenation of Ethane

et al. 2017

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“…Constant value of the conversion of ethane was achieved by changing of catalyst weight (25-450 mg of catalysts diluted with 1 cm 3 silicon carbide inert) at constant total flow of 100 cm 3 min -1 . Finally, the selected Ni-Ce-Al-ac with 0.13 Ce/Ni atomic ratio (3 wt% Ce) was studied under reaction conditions taken from the work of Bortolozzi et al [5], i.e. reaction mixture (comprising 6 vol% C 2 H 6 , 6 vol% O 2 and the rest helium), 300 mg of catalyst, 450°C and total flow of 37.5 cm 3 min -1 (W/F 0.48 g cat s cm -3 STP).…”

Section: Oxidative Dehydrogenation Of Ethanementioning

confidence: 99%

“…Recently, the Ce has been reported as a promoter for Ni-based catalysts used in the oxidative dehydrogenation of ethane [4,5], propane [6][7][8], i-butane [9] and ethylbenzene [10]. The positive effect of Ce on the activity of Ni-based catalysts has also been reported for many other reactions, such as dry reforming of methane [11][12][13], dehydration of diols into unsaturated alcohols [14] and aqueous-phase hydrogenolysis of glycerol [15].…”

Section: Introductionmentioning

confidence: 99%

“…This work follows our previous study [27], where we reported the different activity and selectivity of Ni-Al 2 O 3 catalysts prepared by using of nickel nitrate and nickel acetate possessing a different distribution of Ni(T d ) and Ni(O h ) species. Previously, Bortolozzi et al [5] analysed the effect of cerium as a promoter in Ni-Al 2 O 3 catalysts prepared by nickel nitrate. They reported that cerium improved the ethane conversion due to a synergistic effect with nickel oxide related to the incorporation of the nickel cation into the ceria lattice.…”

Section: Introductionmentioning

confidence: 99%

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The Role of Ni Species Distribution on the Effect of Ce as a Promoter in C2-ODH Reaction

2015

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The aim of work was to analyse and discuss the effect of cerium on the catalytic behaviour of different types of nickel species in the oxidative dehydrogenation of ethane. Ni-Al and Ni-Ce-Al catalysts were prepared from cerium nitrate and nickel nitrate or nickel acetate as a precursor. As-prepared materials were characterized by using of XRD, DR UV-Vis spectroscopy and H 2 -TPR. It was found that the addition of cerium affects both the reducibility of nickel species and the population of nickel species. Firstly, the addition of cerium led to the significant decrease of the reduction peak at 755-785°C to about 40°C due to the Ni-Ce interaction at both Ni-Ce-Al-NO 3 and Ni-Ce-Al-ac catalysts. Secondly, the addition of cerium affected the relative population of nickel species in tetrahedral and octahedral coordination, which population originated from used nickel precursor. The presence of cerium in Ni-Ce-Al-NO 3 catalysts led to the decrease in the relative population of Ni(T d ) species, while the crystal size of NiO in Ni-Ce-Al-ac catalysts decreased with increasing Ce/Ni ratio. The highest ethylene productivity was achieved on catalysts with Ce/Ni molar ratio 0.13. Catalysts exhibited an ethylene productivity up to 1.0 gC 2 =Ág cat -1 Áh -1 with a selectivity of 82 % (Ni-Ce-Al-NO 3 ) and 1.3 gC 2 =Ág cat -1 Áh -1 with a selectivity of 75 % (Ni-CeAl-ac).

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“…Some of them offer lower pressure drop, higher energy efficiency, allow detailed designs, and ease scaling-up, among others [20,21]. The substrates that have been studied for the preparation of structured catalysts are ceramic foams [22], ceramic monoliths [23][24][25], ceramic papers [26][27][28], metallic foams [22,29], and metallic monoliths [5,30].…”

Section: Introductionmentioning

confidence: 99%

FeCrAlloy Monoliths Coated with Ni/Al2O3 Applied to the Low-Temperature Production of Ethylene

et al. 2018

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This paper investigates the oxidative dehydrogenation of ethane to produce ethylene at low temperatures (500 • C) in metallic structured substrates. To check this point, the FeCrAlloy ® monoliths with different channel sizes (289-2360 cpsi) were prepared. The monoliths were coated with a Ni/Al 2 O 3 catalyst (by washcoating of alumina and the latter nickel impregnation) and characterized by Scanning Electron Microscopy and Energy-Dispersive X-ray analysis (SEM-EDX), Temperature-Programmed Reduction (TPR), X-ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). The catalytic results showed that all monoliths coated with~300 mg of catalyst presented similar ethane conversion (15%) at 450 • C. However, the lowest selectivity to ethylene was found for the monolith with the lower channel size and the higher geometric surface area, where a heterogeneous catalyst layer with Ni enriched islands was generated. Therefore, it can be said that the selectivity to ethylene is linked to the distribution of Ni species on the support (alumina). Nevertheless, in all cases the selectivity was high (above 70%). On the other hand, the stability in reaction tests of one of the coated monoliths was done. This structured catalyst proved to be more stable under reaction conditions than the powder catalyst, with an initial slight drop in the first 8 h but after that, constant activity for the 152 h left.

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Efficient structured catalysts for ethylene production through the ODE reaction: Ni and Ni–Ce on ceramic foams

Cited by 17 publications

References 22 publications

Novel Ni-Ce-Zr/Al2O3 Cellular Structure for the Oxidative Dehydrogenation of Ethane

Novel Ni-Ce-Zr/Al2O3 Cellular Structure for the Oxidative Dehydrogenation of Ethane

The Role of Ni Species Distribution on the Effect of Ce as a Promoter in C2-ODH Reaction

FeCrAlloy Monoliths Coated with Ni/Al2O3 Applied to the Low-Temperature Production of Ethylene

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