Synthesis of Three-Dimensionally Ordered Macroporous NiCe Catalysts for Oxidative Dehydrogenation of Propane to Propene

Abstract

Three-dimensionally ordered macroporous (3DOM) NiCe catalysts with different Ni/Ce molar ratio were fabricated using the colloidal crystal templating method. The physic-chemical properties of the samples were characterized by various techniques, including N 2 adsorption-desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman, and H 2 -temperature-programmed reduction (TPR) characterizations. The results revealed that the 3DOM NiCe samples preserved the three-dimensionally ordered macroporous channels with interlinked micro-or mesoporous structure and highly dispersed nickel oxide species in the framework upon different amount of nickel incorporation. In the evaluation of the oxidative dehydrogenation (ODH) of propane, the 3DOM NiCe catalysts exhibited higher selectivity and yield to propene than the amorphous NiCe catalyst. An optimum yield of propene of 11.9% with the 30.3% propane conversion at 375 • C was obtained over the 3DOM 2NiCe catalyst. Combining XRD, TPR, and Raman analysis, it could be found that the nickel incorporation in CeO 2 lattice produced a high concentration of oxygen vacancies that were the active sites for the oxidative dehydrogenation of propane. Besides this, the 3DOM structure promoted the rapid diffusion of the reactants and products-favorable for the generation of propene in the ODH of propane.

High-Performance Vapor-Phase Selective Oxidation of Ethyl Lactate to Ethyl Pyruvate over SiO2 Supported PMoVNb Oxides

“…The SiO 2 and V-Nb/SiO 2 samples exhibit type II adsorption isotherm patterns, which display no adsorption saturation at relatively higher pressure with H3-type hysteresis loops, indicating the existence of the large mesoporous channel structure. The P-Mo-V/SiO 2 , P-Mo-Nb/SiO 2 , and P-Mo-V-Nb/SiO 2 samples have H4 hysteresis loops which adsorption branch is a composite of type I and type II isotherms patterns, suggesting the channel structure with micropores and mesopores [27,28]. Table 1 lists the detailed mesoporous sizes of the sample, which are consistent with the N 2 adsorption isotherm analysis.…”

O2 Activation and Oxidative Dehydrogenation of Propane on Hexagonal Boron Nitride: Mechanism Revisited

“…The oxidative dehydrogenation of propane (ODHP) to propene is an important topic in catalysis and chemical industry, owing to aiming the value-added and synthetically useful chemicals and to reduce environmental pollution. − The scientific challenge of ODHP process remains in the high propane conversion and high propene selectivity. Previous studies showed that the vanadium oxides and cerium oxide catalysts possess the most promising activity for ODHP. ,− However, the most challenge for those catalysts is the low selectivity to propene because propane is more thermodynamically favored to be oxidized to CO or CO 2 . Recently, Grant et al reported that hexagonal boron nitride (h-BN) is a charming metal-free catalyst for ODHP with catalytic performance comparable to that of commercial vanadium oxide catalysts …”

Synthesis, characterization, and evaluation of high selectivity mixed molybdenum and vanadium oxide catalysts for oxidative dehydrogenation of propane

“…The peaks at 2θ =18.2° and 25.0° are related to the MoV 2 O 8 and the peak at 2θ = 21.6° corresponds to the V 2 O 5 . The XRD results in our study show two new peaks: the first peak at 2θ = 44.2° could be attributed to the mixed phase of MoVO x because it appears only in the vanadium‐rich catalyst (MoVO x ‐1); and the second peak at 2θ = 67.5° could be attributed to the molybdenum‐rich phase in other catalysts.…”