Carbon Dioxide to Methane using Ruthenium Nanoparticles: Effect of the Ionic Liquid Media

Abstract

Carbon dioxide hydrogenation to methane is efficiently achieved using ruthenium nanoparticles (Ru NPs) prepared and stabilized in task-specific ionic liquids. 1-Octyl-3methylimidazolim perfluorobutanesulfonate [C 8 mim][NfO] is the best ionic liquid media producing 84% yield of methane at 150 °C. Other fluorinated anions based ionic liquids exhibited a greater influence on the methane production. In parallel, carbon monoxide is selectively produced in a small amount for the ionic liquid media containing trifluoroacetate and mesylate anions. It is known that ionic liquids strongly contribute to higher CO 2 solubility as well as the formation and stabilization of Ru NPs. The catalytic system maintains some activity at least after 5 recycling studies and a promissory improvement can be achieved using a further continuous-flow system.

A Short Review on Ni‐Catalyzed Methanation of CO2: Reaction Mechanism, Catalyst Deactivation, Dynamic Operation

“…However, the reduction of fully oxidized carbon to methane is a process with significant kinetic limitations and, therefore, requires a catalyst to achieve acceptable rates and selectivities [12,13]. Noble metal or nickelbased catalysts are usually applied in methanation [14][15][16].…”

Encapsulation of Ru Complexes into Poly(ionic liquid) Enables the Methanation of CO2 under Mild Conditions

“…44 The selective formation of CO, CH 4 , and C 2+ hydrocarbons under mild conditions was documented by distinct combinations of metal NPs and ILs. 36,37,44,45 Imposed by the good adsorption and activation of CO 2 , ILs also function as promoters or electrolytes to facilitate the electrocatalytic reduction reaction of CO 2 . 46−49 Meanwhile, efforts on immobilizing ILs on the surface of the mesoporous SiO 2 support, followed by impregnation with transitional metal complexes, were successful to deliver supported ionic liquid phase (SILP) catalysts for the hydrogenation of CO 2 and thereby carbonylation.…”

“…The development of catalysts for the methanation of CO 2 at low temperatures, with both high efficiency and selectivity, is still the focus of this field. A survey of the literature reveals that Co, , Ni, , Ru, ,− and Rh 31 -based catalysts allow for low-temperature catalysis, wherein Ru-based catalysts were more extensively studied and exhibited a higher catalytic activity probably due to their better durability than Ni-based catalysts and low cost compared to Rh-based catalysts …”

“…Recent studies further demonstrated that the efficiency of the Ru-catalyzed RWGSR is correlated with a synergetic effect between the cations and anions in imidazolium-based ILs. − On the other hand, transitional metal nanoparticles (NPs) coupled with IL media were well developed in the catalytic hydrogenation of CO 2 primarily because NPs can be highly dispersed in the ILs and exhibit good stability therein . The selective formation of CO, CH 4 , and C 2+ hydrocarbons under mild conditions was documented by distinct combinations of metal NPs and ILs. ,,, Imposed by the good adsorption and activation of CO 2 , ILs also function as promoters or electrolytes to facilitate the electrocatalytic reduction reaction of CO 2 . − Meanwhile, efforts on immobilizing ILs on the surface of the mesoporous SiO 2 support, followed by impregnation with transitional metal complexes, were successful to deliver supported ionic liquid phase (SILP) catalysts for the hydrogenation of CO 2 and thereby carbonylation …”

Low temperature methanation of CO2 over an amorphous cobalt-based catalyst

“…Design of catalysts that can work effectively at lower temperature has received considerable attention. 29 Although many efforts have been made, the progress was restricted to several noble metal catalysts, especially at a temperature below 200 C. [30][31][32][33][34][35][36] Obviously, low temperature methanation of CO 2 over cheap metal catalysts is highly desirable. Herein we show that the amorphous Zrdoped Co-B-O catalyst can effectively accelerate the CO 2 methanation at above 140 C. Excellent activity was obtained at 180 C, which is comparable to or even higher than those of some noble metal catalysts (Table S1 †).…”