CeO₂ Nanorod@NiPhy Core‐shell Catalyst for Methane Dry Reforming: Effect of Simultaneous Sintering Prevention of CeO₂ Support and Active Ni

Abstract

Preventing the sintering of nano-catalyst is crucial to maintain their performance especially for high-temperature reactions such as CO 2 reforming of methane (DRM) reaction. In this paper, we design CeO 2 nanorod@Ni phyllosilicate (CeO 2 @NiPhy) catalysts with different NiPhy shell thickness to simultaneously preserve the morphology of CeO 2 nanorod and prevent the sintering of Ni. Compared with Ni/CeO 2 supported catalyst, CeO 2 @NiPhy core-shell catalyst with a shell thickness of 9 nm exhibits much better performance for DRM with stable CH 4 and CO 2 conversions of 75 % and 80 % respectively and lower carbon deposition due to high Ni sintering resistance and higher thermal stability of CeO 2 during calcination and DRM reaction thereby higher oxygen vacancies concentration. In-situ diffuse reflectance infrared Fourier transform spectra result demonstrates that DRM reaction takes place with a bi-functional mechanism on CeO 2 @NiPhy. This design strategy can be applied to prepare other nano-catalysts with high sintering resistance of both active metal and catalyst support for hightemperature applications.

Catalytic CO2 Conversion to C1 Chemicals over Single‐Atom Catalysts

“…[ 149 ] Nevertheless, non‐noble metal catalysts tend to deactivate quickly due to the rapid coke formation and nanoparticle sintering. [ 140,150 ]…”

“…[149] Nevertheless, non-noble metal catalysts tend to deactivate quickly due to the rapid coke formation and nanoparticle sintering. [140,150] Reducing the size of metal particles can significantly enhance the activity while inhibiting the undesirable coking of metal catalysts, so SACs with isolated metal atom as active sites are increasingly used in DRM reactions, as shown in Table 1. Akri et al found that Ni single atoms supported by hydroxyapatite (0.5Ni 1 /HAP) possessed a much more superior coke resistance ability with negligible coke deposition, compared to 10Ni/HAP (Insets: Raman spectra of spent 0.5Ni 1 /HAP and 10Ni/HAP catalysts and STEM image of spent 0.5Ni 1 /HAP catalyst after reaction at 750 °C for 7 h).…”

Smart Designs of Zeolite-Based Catalysts for Dry Reforming of Methane: A Review

“…To address the deactivation issues in the DRM process, tremendous efforts have been dedicated to the modification of catalysts. − For example, the doping of W and Si facilitated the Ni aluminate formation in Ni/Al 2 O 3 catalysts, in which Ni was highly dispersed and anchored onto the support due to the strong interaction, thus preventing coke formation . Besides the strong metal–support interactions, Ni nanoparticles with an average size of 4.3 nm were confined within the porous carbon derived from pinewood sawdust, inhibiting the metal agglomeration (4.6 nm after 500 min DRM reaction at 700 °C) .…”