Highly active and stable nano NiO–MgO catalyst encapsulated by silica with a core–shell structure for CO₂ methanation

Abstract

Ni–MgO nanoparticles (NPs) encapsulated by porous silica shell for CO2 methanation were synthesized.

The difference of roles of alkaline-earth metal oxides on silica-supported nickel catalysts for CO2 methanation

“…13 Some supported or non-supported transition metal catalysts have acceptable performance, such as Ni, 8,9,[14][15][16][17][18][19] Co 20-23 and Fe. 20,24 Moreover, the promotion effect of second transition metal addition to the Ni-based catalysts has also been reported.…”

A novel W-doped Ni-Mg mixed oxide catalyst for CO2 methanation

“…Further modifications of the surface properties can be achieved by controlling the formation of 'ideal' Ni-Mg solid solution [21,22]. Ni-MgO nanoparticles encapsulated by porous silica shell, reveals a remarkable improvement in CO 2 conversion with high stability compared to the encapsulated NiO without MgO [23]. To the contrary, the presence of MgO is considered to lower the methanation activity due to the poor reducibility of Ni-Mg solid solution [24].…”

“…The stability enhancement over their catalysts was attributed to the 'anchoring' of metallic Ni by surface defects on the support, which were formed at the vicinity of the reduction sites of Ni species located in the Ni-Mg solid solution. Furthermore, the incorporation of a third component, such as Ru [23], Sr [29], Co [30] has been investigated to improve the stability of Ni-based catalysts for CO 2 methanation. Recently, a synergistic effect between Ni and W in mixed Ni-W-Ce oxide catalysts has been reported, which displayed significant effectiveness in minimizing the coke formation and stabilizing the metal particles for ethanol steam reforming [31].…”

Nickel supported on iron-bearing olivine for CO2 methanation

“…It contains (Mg x Fe 1Àx ) 2-SiO 4 as the main phase and small quantities of MgSiO 3 and FeO x species [35e37]. The interactions between supported NiO and (Mg x Fe 1Àx ) 2 SiO 4 might lead to NiOeMgO solid solution formation [36], which was reported to be helpful in enhancing Ni species dispersion and stability of the Ni/olivine [36,38,39]. More importantly, the olivine could be a source of Fe for the supported bimetallic NieFe catalysts.…”