Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Mar 17;1(4):450-458.
doi: 10.1021/jacsau.1c00021. eCollection 2021 Apr 26.

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

Scott R Docherty  1 , Nat Phongprueksathat  2 , Erwin Lam  1 , Gina Noh  1 , Olga V Safonova  3 , Atsushi Urakawa  2 , Christophe Copéret  1
Affiliations

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

Scott R Docherty et al. JACS Au. .

Erratum in

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.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing financial interest.

Figures

Scheme 1
Scheme 1. (a) Thermodynamics of CO2 Hydrogenation. (b) Comparison of Reported Pd/Ga Systems and This Work
Figure 1
Figure 1
(a) Synthetic procedure for PdGa@SiO2. (b) Particle size distribution and representative TEM images for PdGa@SiO2; and (c) CO-adsorption IR for (i) PdGa@SiO2 exposed (purple, top) and prior to CO adsorption (gray, bottom); (ii) Pd@SiO2 exposed (green, top) and prior to CO adsorption (gray, bottom). 10 mbar CO.
Figure 2
Figure 2
Normalized XANES spectra for (a) Ga K edge, (b) first derivative Ga K edge–Ga metal (dark gray), PdGa@SiO2 (blue), Ga@SiO2 (green), and β-Ga2O3 (light gray); (c) Pd K edge–Pd foil (dark gray), PdGa@SiO2 (blue), Pd@SiO2 (red), and PdO (light gray); and Pd K edge EXAFS fits (d) PdGa@SiO2 and (e) Pd@SiO2 (k-weight: 3, fit in light gray).
Figure 3
Figure 3
(left) Formation rates for PdGa@SiO2, Pd@SiO2, Cu–Ga@SiO2, and Cu@ZrO2. (right) Selectivity as a function of conversion for PdGa@SiO2, Cu–Ga@SiO2, Cu@SiO2, Cu@ZrO2. Conditions: 3:1:1 H2/CO2/Ar, 25 bar, 230 °C, 200 mg of catalyst, 5 g of SiC, 6–100 sccm.
Figure 4
Figure 4
IR analysis after exposure to CO2/H2 (3:1) at 230 °C and 5 bar for (a) PdGa@SiO2 exposed (purple, top) and prior to exposure to reaction gases (gray, bottom); (b) Pd@SiO2 exposed (green, top) and prior to exposure to reaction gases (gray, bottom). Reaction time: 12 h.
Figure 5
Figure 5
Operando DRIFTS spectra for (a, b) PdGa@SiO2 under H2/CO2 at steady state (3:1, 20 bar, 230 °C); (c) MCR-resolved component profiles, and (d) MCR-resolved concentrations for PdGa@SiO2 under both CO2/He (1:3) and H2/He (3:1). Conditions: 20 bar, 230 °C.
See this image and copyright information in PMC

References

    1. Kondratenko E. V.; Mul G.; Baltrusaitis J.; Larrazábal G. O.; Pérez-Ramírez J. Status and Perspectives of CO2 Conversion into Fuels and Chemicals by Catalytic, Photocatalytic and Electrocatalytic Processes. Energy Environ. Sci. 2013, 6 (11), 3112–3135. 10.1039/c3ee41272e. - DOI
    1. Goeppert A.; Czaun M.; Jones J.-P.; Surya Prakash G. K.; Olah G. A. Recycling of Carbon Dioxide to Methanol and Derived Products – Closing the Loop. Chem. Soc. Rev. 2014, 43 (23), 7995–8048. 10.1039/C4CS00122B. - DOI - PubMed
    1. Olah G. A. Towards Oil Independence Through Renewable Methanol Chemistry. Angew. Chem., Int. Ed. 2013, 52 (1), 104–107. 10.1002/anie.201204995. - DOI - PubMed
    1. Álvarez A.; Bansode A.; Urakawa A.; Bavykina A. V.; Wezendonk T. A.; Makkee M.; Gascon J.; Kapteijn F. Challenges in the Greener Production of Formates/Formic Acid, Methanol, and DME by Heterogeneously Catalyzed CO2 Hydrogenation Processes. Chem. Rev. 2017, 117 (14), 9804–9838. 10.1021/acs.chemrev.6b00816. - DOI - PMC - PubMed
    1. Jiang X.; Nie X.; Guo X.; Song C.; Chen J. G. Recent Advances in Carbon Dioxide Hydrogenation to Methanol via Heterogeneous Catalysis. Chem. Rev. 2020, 120 (15), 7984–8034. 10.1021/acs.chemrev.9b00723. - DOI - PubMed