Synthesis of a SiO₂ nanofibre confined Ni catalyst by electrospinning for the CO₂ reforming of methane

Abstract

A silica (SiO 2 ) nanofibre confined nickel (Ni) catalyst was successfully synthesized by the electrospinning technique and was then systematically characterized with thermogravimetric/differential thermal analysis (TG/DTA), X-ray photoelectron spectroscopy (XPS), N 2 sorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution-transmission electron microscopy (HR-TEM), temperatureprogrammed oxidation (O 2 -TPO), temperature-programmed reduction (H 2 -TPR) and temperatureprogrammed desorption (CO 2 -TPD) measurements. In the electrospinning synthesized Ni/SiO 2 catalyst, most of the Ni nanoparticles were confined inside SiO 2 nanofibers with an average particle size of 8.1 nm.Compared with the Ni/SiO 2 catalyst conventionally prepared via the incipient impregnation method using commercial SiO 2 powder as the support, the electrospun Ni/SiO 2 catalyst exhibited improved metal dispersion and enhanced metal-support interaction, leading to slightly higher activity and much better stability in the carbon dioxide (CO 2 ) reforming of methane. Carbon deposition, rather than metal sintering, is identified as the main cause for the deactivation of the Ni/SiO 2 catalyst under current conditions. The present work demonstrates that electrospinning is a potential technique for the fabrication of nanoconfined catalysts with superior catalytic performance and macro-scale handling properties.

Catalytic Conversion of Carbon Oxides in Confined Spaces: Status and Prospects

“…The restrained sintering and coking by confined spaces are extensively investigated and applied to diverse reactions including but not being limited to CO x conversion. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] The intensified metal-support interaction by confinement effect can inhibit the formation of shell carbon, and therefore, the accessibility of active sites is not depressed. As a consequence, the catalytic activity can be maintained during the reaction.…”

“…Silica nanofiber confined Ni by electrospinning, higher Ni dispersion, slightly higher activity [26] Ni@Al 2 O 3 CO 2 -to-syngas by dry reforming of CH 4…”

“…[8,[14][15][16][17][18][19][20][21][22][23] Currently, confinement catalysis has been extensively applied to the catalytic conversion of CO x regarding of improvement in catalytic activity, selectivity, and stability (Scheme 1). [9][10][11][12][24][25][26] Especially, the confined spaces of catalysts efficiently improve the catalytic selectivity for CO x conversion into fuels and high-value chemicals through the modulation of active sites and also the products self-regulation by the confined shell, which represents a promising direction for the selective conversion and utilization of carbon oxides.…”

Enhanced low‐temperature activity for CO2 methanation over NiMgAl/SiC composite catalysts

“…The existence of side reaction, Boudouard reaction, would result in carbon deposition . It is generally agreed that carbon deposition is sensitive to Ni particle size . Therefore, TEM and TGA characterizations were carried out on the spent NiMgAl/SiC catalyst.…”

“…8,26 It is generally agreed that carbon deposition is sensitive to Ni particle size. 16,38 Therefore, TEM and TGA characterizations were carried out on the spent NiMgAl/SiC catalyst. As shown in Fig.…”