NO oxidation over Ni–Co perovskite catalysts

Zhong, Shifa; Sun, Yuanyuan; Xin, Hongchuan; Yang, Chunpeng; Chen, Lei; Li, Xuebing

doi:10.1016/j.cej.2015.04.046

Cited by 71 publications

(18 citation statements)

References 25 publications

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“…8 13 The XRD patterns shown in Figure 1 reveal the formation of phase-pure perovskite structure for all samples, and no peaks characteristic of the metallic oxides or carbonates were seen. The main characteristic peak at 2θ = 33 • for LaCoO 3 slightly shifts towards lower 2θ values with an increase in x and y, indicating an increase in the lattice parameters confirming previous findings [13,19,20]. This expansion can be explained by comparing the ionic radii of the species in the perovskite structure.…”

Section: Catalyst Characterisationsupporting

confidence: 88%

Catalytic Oxidation of NO over LaCo1−xBxO3 (B = Mn, Ni) Perovskites for Nitric Acid Production

et al. 2019

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Nitric acid (HNO3) is an important building block in the chemical industry. Industrial production takes place via the Ostwald process, where oxidation of NO to NO2 is one of the three chemical steps. The reaction is carried out as a homogeneous gas phase reaction. Introducing a catalyst for this reaction can lead to significant process intensification. A series of LaCo1−xMnxO3 (x = 0, 0.25, 0.5 and 1) and LaCo1−yNiyO3 (y = 0, 0.25, 0.50, 0.75 and 1) were synthesized by a sol-gel method and characterized using N2 adsorption, ex situ XRD, in situ XRD, SEM and TPR. All samples had low surface areas; between 8 and 12 m2/g. The formation of perovskites was confirmed by XRD. The crystallite size decreased linearly with the degree of substitution of Mn/Ni for partially doped samples. NO oxidation activity was tested using a feed (10% NO and 6% O2) that partly simulated nitric acid plant conditions. Amongst the undoped perovskites, LaCoO3 had the highest activity; with a conversion level of 24.9% at 350 °C; followed by LaNiO3 and LaMnO3. Substitution of LaCoO3 with 25% mol % Ni or Mn was found to be the optimum degree of substitution leading to an enhanced NO oxidation activity. The results showed that perovskites are promising catalysts for NO oxidation at industrial conditions.

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Section: Catalyst Characterisationsupporting

confidence: 88%

Catalytic Oxidation of NO over LaCo1−xBxO3 (B = Mn, Ni) Perovskites for Nitric Acid Production

et al. 2019

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“…Figure 6A shows that three reduction peaks appear in the H 2 -TPR profile. According to literature, the first two peaks were attributed to the removal of oxygen species adsorbed on oxygen vacancies and the reduction of Co 3+ to Co 2+ (or Ni 3+ to Ni 2+ ), respectively, and the third peak is to the reduction of Co 2+ to Co 0 , (or Ni 2+ to Ni 0 ) [34]. For comparison, the reduction profile of pure NiO was also conducted,…”

Section: Catalyst Characterizationmentioning

confidence: 99%

Comparison of the nickel addition patterns on the catalytic performances of LaCoO3 for low-temperature CO oxidation

Wan³

et al. 2017

Catalysis Today

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Effect of nickel on the catalytic performances of LaCoO 3 for CO oxidation is investigated, by partial substitution of Co with Ni atoms in the framework or by deposition of NiO on the surface of LaCoO 3. Results show that the activity decreases in order of 10%Ni/LaCoO 3 > LaCoO 3 > LaCo 0.8 Ni 0.2 O 3 , with the CO ignition temperature of 60, 110 and 140 °C, respectively (reaction conditions: 0.5% CO/Ar and 7.5 % O 2 /Ar, balanced with Ar; space velocity of 30000 mL g-1 h-1). Based on the characterizations such as XPS, H 2-TPR, O 2-TPD and CV measurements, we inferred that the high activity of 10%Ni/LaCoO 3 is attributed to a synergistic effect induced by NiO and LaCoO 3 , and the low activity of LaCo 0.8 Ni 0.2 O 3 is to the enrichment of La atoms on the surface, caused by the Ni incorporation. Long-time stability test indicates that 10%Ni/LaCoO 3 is stable in the reaction, with no appreciable loss of activity within 32 h. The highly active and stable activity of 10%Ni/LaCoO 3 suggests that impregnation of metal oxides on the surface of perovskite can be a feasible strategy for the preparation of industrial catalyst for CO oxidation.

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“…Thus, the catalytic oxidation of NO to NO 2 over the γ-MnO 2 catalyst was investigated, and the results in Fig. 1b indicate that the oxidation reaction is kinetically limited at low temperature and becomes thermodynamically controlled at high temperature [23][24][25]. Obviously, γ-MnO 2 exhibits good catalytic behavior for NO oxidation, and obtains the maximum NO conversion of 93% at 220 °C, which is even better than the activity of some noble metals [26,27].…”

Section: Catalytic Activity Of the γ-Mno 2 Catalystmentioning

confidence: 97%

In-Situ DRIFTS for Reaction Mechanism and SO2 Poisoning Mechanism of NO Oxidation Over γ-MnO2 with Good Low-Temperature Activity

2018

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In this study, the γ-MnO 2 catalyst modified with PEG exhibits outstanding low-temperature performances for NO oxidation, and in-situ DRIFTS experiments were used to systematically investigate the low-temperature NO oxidation mechanisms over γ-MnO 2 . These results demonstrated that NO was first adsorbed on the surface of γ-MnO 2 to form the nitrosyls, which could be further oxidized to nitrates under the action of the chemisorbed oxygen or lattice oxygen, and afterwards the formed nitrates were decomposed into nitrogen dioxide. Moreover, the inhibitory mechanism of SO 2 on γ-MnO 2 was also studied, and SO 2 severely inhibit the NO oxidation performance of γ-MnO 2 through forming stable sulfates that could easily consume the active sites of the catalyst to hinder the formation of nitrates, resulting in the termination of oxidation of NO to NO 2 . Clarifying the mechanisms of NO oxidation and SO 2 poison is very essential for developing better NO oxidation catalysts.

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NO oxidation over Ni–Co perovskite catalysts

Cited by 71 publications

References 25 publications

Catalytic Oxidation of NO over LaCo1−xBxO3 (B = Mn, Ni) Perovskites for Nitric Acid Production

Catalytic Oxidation of NO over LaCo1−xBxO3 (B = Mn, Ni) Perovskites for Nitric Acid Production

Comparison of the nickel addition patterns on the catalytic performances of LaCoO3 for low-temperature CO oxidation

In-Situ DRIFTS for Reaction Mechanism and SO2 Poisoning Mechanism of NO Oxidation Over γ-MnO2 with Good Low-Temperature Activity

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