Tunable colloidal Ni nanoparticles confined and redistributed in mesoporous silica for CO₂ methanation

Abstract

Colloidal Ni nanoparticles were prepared using seed-mediated strategies and encapsulated in mesoporous silica to yield stable and sinter-resistant hydrogenation catalysts.

Green Synthetic Fuels: Renewable Routes for the Conversion of Non-Fossil Feedstocks into Gaseous Fuels and Their End Uses

“…The deposition of dopants (i.e., ZrO 2 ) onto the catalyst surface [585] and the encapsulation of colloidal catalyst nanoparticles prevent the degradation process [586]. Further, the regeneration of the deactivated catalysts due to sintering and carbon deposition is practicable.…”

Ceria–zirconia encapsulated Ni nanoparticles for CO2 methanation

“…The encapsulated NiIJ4.4)@SiO 2 catalyst was characterized and discussed in more detail in earlier work (see ref. 49).…”

“…Our recent work reported that colloidal Ni nanoparticles (NiNPs) can be synthesized with sizes in the 3-8 nm range by employing a seed-mediated approach. 49 An effective strategy to support such NiNPs and obtain active hydrogenation catalysts was to encapsulate them in a silica (SiO 2 ) support grown around the NiNPs. Work by Pu et al highlighted the possibility of encapsulating Ni particles in supports other than SiO 2 including Al 2 O 3 , TiO 2 and CeO 2 , although the final particle sizes were significantly larger than those of conventional Ni-based hydrogenation catalysts.…”

“…The catalytic activity and stability of the resulting Ni@CZ in CO 2 methanation were superior in comparison to a Ni/CZ catalyst synthesized via incipient-wetness impregnation (IWI [51][52][53] as described in our previous work. 49 To summarize, a 250 mL two-neck round-bottomed flask with a magnetic stirring bar was loaded with 257 mg NiIJacac) 2 (1 mmol), 15 mL oleylamine (OAm) and 0.32 mL oleic acid (OAc, 1 mmol) and brought under inert conditions in Ar. To remove oxygen and water, the mixture was heated to 110°C under Ar and rigorous stirring, and degassed for 30 min to yield a green-blue solution.…”

In SituShell‐Isolated Nanoparticle‐Enhanced Raman Spectroscopy of Nickel‐Catalyzed Hydrogenation Reactions

“…The Ni(Col) and Ni(Pr)/Au@SiO 2 samples had to undergo reduction treatment at high temperature first. Temperature Programmed Reduction (TPR) of the colloidal Ni NPs [41] gave a required reduction temperature in H 2 of 450-600°C to fully reduce the passivated Ni NPs to their metallic phase. However, due to the limited stability of Au@SiO 2 at high temperatures and the practical limitations of the Linkam Cell brought about by the high heat capacity of H 2 , the maximum temperature that can be reliably achieved is 400°C.…”