Ni‐Ce/Zeolites for CO₂ Hydrogenation to CH₄: Effect of the Metal Incorporation Order

Abstract

a] InÞsG raÅa, [b] JosØ M. Lopes, [a] andC arlosH enriques* [a] Introduction CO 2 methanation, as af orm of alleviating CO 2 emissions, has been the focus of much attention in the last few years, with thermal, photocatalytic,e lectrochemical, or even plasma assisted processes being used. [1][2][3][4][5][6] Ni and Ru-based materials have been commonly used for this reaction, on different supports, such as Al 2 O 3 , [7][8][9][10][11][12][13][14][15] SiO 2 , [16][17][18][19][20] Ce and Zr oxides, [21][22][23][24][25][26][27][28] hydrotalcites and hydrotalcite-derived materials, [21,[29][30][31][32] carbon nanotubes, [33][34][35][36][37] mesoporous materials, [38][39][40][41][42][43] and zeolites. [44][45][46][47][48][49] Amongt he different supports used, zeolitesh ave been revealed to be interesting materials, as their properties (e.g.,S i/ Al ratio, compensating cation) can be easily modified to meet the requirements of the reaction.Ni-basedu ltrastable Yz eolites (USY) have been appliedt o the CO 2 methanation reaction, with very promising results. [44][45][46][47][48][49] In these studies, changes to the metal incorporation method (impregnation or ion-exchange), the preparation conditions, the type of compensating cation, and the Si/Al ratio have been investigated to try to obtain an optimized catalyst formulation. [44][45][46] In addition, some highlights into the mechanism and [a] M.

Tuning Zeolite Properties towards CO2 Methanation: An Overview

“…In addition, Bacariza et al . optimized the impregnation strategy for the synthesis of NiCe/USY zeolites (Figure ).…”

“…Authors found out that co‐impregnation favours Ni and Ce species interaction, enhancing the metallic dispersion and the CO 2 adsorption/activation. Indeed, the optimized sample reported by the authors in this work presented higher performances than a commercial Ni‐based alumina catalyst…”

“… Performances reported by Bacariza et al . for sequentially (Ce/Ni) and simultaneously (Ni−Ce) impregnated NiCe/Zeolites.…”

“…Additionally, they observed a remarkable effect derived from cerium incorporation, being the performances again better than the ones obtained for a commercial catalyst. These effects had already been reported under thermal assisted methanation by the same authors, but they are even more remarkable under DBD plasma conditions …”

“…In addition, Bacariza et al [48] optimized the impregnation strategy for the synthesis of NiCe/USY zeolites ( Figure 5). Authors found out that co-impregnation favours Ni and Ce species interaction, enhancing the metallic dispersion and the CO 2 adsorption/activation.…”