Catalytic Hydrogenation of CO2 to Methanol over Cu/MgO Catalysts in a Semi-Continuous Reactor

Abstract

Methanol synthesis from carbon dioxide (CO2) may contribute to carbon capture and utilization, energy fluctuation control and the availability of CO2-neutral fuels. However, methanol synthesis is challenging due to the stringent thermodynamics. Several catalysts mainly based on the carrier material Al2O3 have been investigated. Few results on MgO as carrier material have been published. The focus of this study is the carrier material MgO. The caustic properties of MgO depend on the caustification/sintering temperature. This paper presents the first results of the activity of a Cu/MgO catalyst for the low calcining temperature of 823 K. For the chosen calcining conditions, MgO is highly active with respect to its CO2 adsorption capacity. The Cu/MgO catalyst showed good catalytic activity in CO2 hydrogenation with a high selectivity for methanol. In repeated cycles of reactant consumption and product condensation followed by reactant re-dosing, an overall relative conversion of CO2 of 76% and an overall selectivity for methanol of 59% was obtained. The maximum selectivity for methanol in a single cycle was 88%.

CO Hydrogenation to Methanol over Cu/MgO Catalysts and Their Synthesis from Amorphous Magnesian Georgeite Precursors

“…Studt et al. highlighted the role of CO 2 as a suppressor of CO conversion; [5] nevertheless, prospects for CO 2 hydrogenation over Cu/MgO were recently reported by Kleiber et al [14] …”

Direct Reduction of Siderite Ore Combined with Catalytic CO/CO2 Hydrogenation to Methane and Methanol: A Technology Concept

“…(2) Wet impregnation: The calcined MgO was impregnated with nickel or copper(II) nitrate solution, stirred in a water cooled flask for 2 h, filtered off, and dried overnight. The impregnation is described in detail in Loder et al [22] and Kleiber et al [23].…”

“… Wet impregnation: The calcined MgO was impregnated with nickel or copper(II) nitrate solution, stirred in a water cooled flask for 2 h, filtered off, and dried overnight. The impregnation is described in detail in Loder et al 22 and Kleiber et al 23. Thermal decomposition: The Ni‐based catalyst precursor was calcined in the muffle furnace for 2 h at 393 K followed by 5 h at 673 K (Eq. 13).…”

“…As MgO is a slag-former, it can easily be recycled in the blastoxygen furnaces in the copper and steel industry and, thus, fulfills the criterion of recyclability. To prove this concept, bifunctional Ni-and Cu-based catalyst on MgO carrier material were prepared by wet impregnation and successfully applied for CO 2 hydrogenation to methane and methanol [21][22][23].…”

“…To close the raw material cycle and provide a complete technology concept for iron production based on the direct reduction of siderite ore, MgO stands out as a suitable carrier material for the catalytically active components Ni and Cu. Due to its CO 2 adsorption capacity it gives access to bifunctional catalysts [21][22][23][24][25]. At the end of their lifetime, the spent Ni/MgO and Cu/MgO catalysts from methane and methanol synthesis, respectively, can easily be recycled in the blast-oxygen furnaces in the steel and copper industry, as MgO acts as a suitable slagformer.…”