Promoting Methanol Synthesis and Inhibiting CO₂ Methanation with Bimetallic In–Ru Catalysts

Abstract

In this work, we investigated the promotional effects of In on Ru for the synthesis of methanol via CO 2 hydrogenation in the liquid phase. Incorporation of In to Ru results in a methanol selectivity of ∼85% at 240 °C and 3.4 MPa (CO 2 /H 2 = 1 / 3 ). Additionally, no methane was observed under the conditions studied (200−240 °C). The combination of In and Ru modulates Ru sites geometrically and electronically. X-ray diffraction and X-ray photoelectron spectroscopy provided evidence of the structural evolution from mixed metal oxides to alloy and intermetallic phases and charge transfer from In to Ru, respectively. Additionally, in situ diffuse reflectance infrared Fourier transform spectroscopy studies using probe molecules (CO 2 +H 2 , CO, formic acid, methanol), as well as CO-temperatureprogrammed reaction and H 2 -D 2 exchange experiments, were conducted to provide insight into the promotional effect of In. With the incorporation of In, surface formate and methoxy species were stabilized to promote the formation of methanol. Methanation, which is a dominant pathway on monometallic Ru, was inhibited with promoter addition.

A critical review of technologies, costs, and projects for production of carbon-neutral liquid e-fuels from hydrogen and captured CO2

“…90 Ru-based catalysts have been recently explored for their potential in the synthesis of e-methanol from H 2 /CO 2 and incorporating Ru with indium (In) has been shown to prevent methanation and instead produce methanol with 485% selectivity. 90 Other laboratory-scale advancements in preventing methanation include coating ruthenium with a thin layer of a porous plastic/polymer. 91,92 In the case of a two-step process for e-methanol production that also includes a high-temperature RWGS reactor (usually the case, as shown in Fig.…”

“…Ruthenium (Ru)-based catalysts have been used to convert CO 2 to CH 4 (e.g., via the Sabatier methanation process) with a selectivity between 99 and 100% over a range of operating temperatures, from a low of 60 1C to a high of B450 1C. 90 Ru-based catalysts have been recently explored for their potential in the synthesis of e-methanol from H 2 /CO 2 and incorporating Ru with indium (In) has been shown to prevent methanation and instead produce methanol with 485% selectivity. 90 Other laboratory-scale advancements in preventing methanation include coating ruthenium with a thin layer of a porous plastic/polymer.…”

A Computational Map of the Probe Co Molecule Adsorption and Dissociation on Transition Metal Low Miller Indices Surfaces

“…Such trends are also observed on CO dissociation ΔE vs ε d , revealing that such a reaction is highly endothermic for a series of TMs, mostly fcc late TMs, excessively exothermic for another series of TMs, mostly bcc TMs, while hcp values are spread; only those TMs of Groups VII, VIII, and IX feature moderate ΔE values adequate for the catalysis involving the CO dissociation, while late TMs are thus more suited when involving a catalysis where the CO integrity needs to be maintained, e.g. in the course of CO 2 hydrogenation towards methanol, carried out in Groups IX (Rh, Ir), X (Ni, Pd, Pt), and XI (Cu, Ag, Au) [51][52][53][54][55][56][57].…”

Noble Metals in Recent Developments of Heterogeneous Catalysts for CO2Conversion Processes

“…Geng et al [106] published the first work applying Ru-based catalysts to produce methanol from CO 2 hydrogenation reaction using a batch reactor in 2020. They studied bimetallic phosphides using RuÀ Mo at different RuÀ Mo [107] investigated the promotional effects of In on Ru catalyst, a catalyst most known and used in CO 2 methanation reaction. They observed that the incorporation of In inhibited methane formation and promoted methanol formation in a batch reactor (methanol selectivity > 85 %).…”