Exclusive Hydrogen Generation by Electrocatalysts Coated with an Amorphous Chromium-Based Layer Achieving Efficient Overall Water Splitting
KAUST DepartmentCatalysis for Energy Conversion (CatEC)
Chemical Science Program
KAUST Catalysis Center (KCC)
Physical Science and Engineering (PSE) Division
Online Publication Date2017-08-15
Print Publication Date2017-09-05
Permanent link to this recordhttp://hdl.handle.net/10754/625383
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AbstractSuccessful conversion of renewable energy to useful chemicals requires efficient devices that can electrocatalyze or photocatalyze redox reactions, e.g., overall water splitting. Excellent electrocatalysts for the hydrogen evolution reaction (HER), such as Pt, can also cause other side-reactions, including the water-forming back-reaction from H2 and O2 products. A Cr-based amorphous layer coated on catalysts can work as a successful surface modifier that avoids the back-reaction, but its capabilities and limitations toward other species have not been studied. Herein, we investigated the Cr-based layer on Pt from perspectives of both electrocatalysis and photocatalysis using redox-active molecules/ions (O2, ferricyanide, IO3–, S2O82–, H2O2, and CO gas). Our systematic study revealed that utilization of the Cr-based layer realized an exclusive cathodic reaction only to HER, even in the presence of the aforementioned reactive species, suggesting that Cr-based layers work as membranes, as well as corrosion and poison inhibition layers. However, the Cr-based layer experienced self-oxidation and dissolved into the aqueous phase when a strong oxidizing agent or low pH was present. Presented herein are fundamental and critical aspects of the Cr-based modifier, which is essential for the successful and practical development of solar fuel production systems.
CitationQureshi M, Shinagawa T, Tsiapis N, Takanabe K (2017) Exclusive Hydrogen Generation by Electrocatalysts Coated with an Amorphous Chromium-Based Layer Achieving Efficient Overall Water Splitting. ACS Sustainable Chemistry & Engineering. Available: http://dx.doi.org/10.1021/acssuschemeng.7b01704.
SponsorsThe authors thank Dr. Dalaver H. Anjum for the TEM images. The research reported in this work was supported by the King Abdullah University of Science and Technology.
PublisherAmerican Chemical Society (ACS)