Silica-Supported PdGa Nanoparticles: Metal Synergy for Highly Active and Selective CO2-to-CH3OH Hydrogenation


Date

2021-04-26

Publication Type

Journal Article, Journal Article

ETH Bibliography

yes

Citations

Altmetric

Data

Abstract

The direct conversion of CO2 to CH3OH represents an appealing strategy for the mitigation of anthropogenic CO2 emissions. Here, we report that small, narrowly distributed alloyed PdGa nanoparticles, prepared via surface organometallic chemistry from silica-supported GaIII isolated sites, selectively catalyze the hydrogenation of CO2 to CH3OH. At 230 °C and 25 bar, high activity (22.3 molMeOH molPd–1 h–1) and selectivity for CH3OH/DME (81%) are observed, while the corresponding silica-supported Pd nanoparticles show low activity and selectivity. X-ray absorption spectroscopy (XAS), IR, NMR, and scanning transmission electron microscopy–energy-dispersive X-ray provide evidence for alloying in the as-synthesized material. In situ XAS reveals that there is a dynamic dealloying/realloying process, through Ga redox, while operando diffuse reflectance infrared Fourier transform spectroscopy demonstrates that, while both methoxy and formate species are observed in reaction conditions, the relative concentrations are inversely proportional, as the chemical potential of the gas phase is modulated. High CH3OH selectivities, across a broad range of conversions, are observed, showing that CO formation is suppressed for this catalyst, in contrast to reported Pd catalysts.

Publication status

published

Editor

Book title

Journal / series

Volume

1 (4)

Pages / Article No.

450 - 458

Publisher

American Chemical Society

Event

Edition / version

Methods

Software

Geographic location

Date collected

Date created

Subject

CO2 hydrogenation; Heterogeneous catalysis; Alloys; Nanoparticles; Operando spectroscopy; Hydrogenation

Organisational unit

03872 - Copéret, Christophe / Copéret, Christophe check_circle
02513 - Laboratorium für Anorganische Chemie / Laboratory of Inorganic Chemistry

Notes

Funding

183495 - Tailored CO2 Hydrogenation Catalysts for Selective Methanol Synthesis via Structure-Activity Relationship across Time and Length Scale (SNF)
169134 - Molecular Approach to Heterogeneous Catalysis (SNF)

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