Chem Catalysis

Chem Catalysis

Volume 2, Issue 6, 16 June 2022, Pages 1440-1449
Journal home page for Chem Catalysis

Article
Photo-splitting of water toward hydrogen production and active oxygen species for methane activation to methanol on Co-SrTiO3

https://doi.org/10.1016/j.checat.2022.04.008Get rights and content
Under a Creative Commons license
open archive

Highlights

  • •

    Photocatalytic water splitting to H2 coupled with CH4 activation is proposed

  • •

    In-situ-generated OH not only provides well activity but also avoids CH3OH oxidation

  • •

    The coupled strategy provides new insights into H2 production from H2O photo-splitting

  • •

    The in-situ-formed active O provides new insights into selective oxidation of the C-H bond

The bigger picture

Methane, the major constituent in natural gas, has drawn tremendous attention not only as fuel but also as a C1 building block for producing chemicals. The high dissociation energy (439 kJ mol−1) and nonpolar nature of the inert C-H bond of CH4 make activation of the C-H bond under moderate conditions a great challenge. Here we propose a strategy for activation of the C-H bond in CH4 via the active O species generated from photo-splitting of H2O, simultaneously generating value-added CH3OH and H2.

The in-situ-generated active OH radical not only provides excellent activity but also avoids further oxidation of the formed CH3OH, giving 1.84 mmol gCo−1 h−1 of CH3OH formation with an extraordinary selectivity of 98.7%. The coupled strategy also provides new insight into H2 production from photocatalytic H2O splitting, 2.4 times better efficacy than that from overall photocatalytic H2O splitting.

Summary

Direct activation of the C-H bond of CH4 under moderate conditions is highly desired but a great challenge. This work proposes a strategy for activation of the C-H bond in CH4 via the active O species generated from photo-splitting of H2O, simultaneously generating value-added CH3OH and H2. This has been achieved on SrTiO3-supported Co particles with abundant Co-SrTiO3 interfacial sites in which H2O is photo-oxidized on SrTiO3 to H2O2, which then decomposes to the active OH radical to attack the activated CH4 on the Co particle. As a result, 1.84 mmol h−1 on per gram of Co (mmol gCo−1 h−1) of CH3OH with an extraordinary selectivity of 98.7% was obtained, and the efficiency of H2 production improved to 2.4 times higher than that from overall photocatalytic H2O splitting.

Keywords

photo-splitting of water
hydrogen production
active oxygen species
methane activation
methanol

UN Sustainable Development Goals

SDG7: Affordable and clean energy

Data and code availability

The study did not report the availability of any unpublished custom code, software, or algorithm that is central to supporting the main claims of the paper.

Cited by (0)

3

Lead contact

© 2022 Elsevier Inc.