Abstract
Pertinent existing hydrogen technologies for energy storage require unsustainable amounts of scarce platinum group metals. Here, an electrocatalyst comprising high-aspect-ratio platinum nanowires (PtNWs) on single-walled carbon nanotubes (SWNTs) with ultralow Pt content (340 ngPt cm−2) is employed for hydrogen evolution reaction (HER). A comparable activity (10 mA cm−2 at −18 mV vs. RHE) to that of state-of-the-art Pt/C (38,000 ngPt cm−2) is reached in acidic aqueous electrolyte. This is attributed to favorable PtNW interaction with SWNTs and PtNW edge-sites which adsorb hydrogen optimally and aid at alleviating repulsive interactions. Moreover, the metallic nature of Pt, morphological effects and enhanced wetting contribute positively. The PtNW/SWNT relevance is emphasized at a proton-exchange-membrane electrolyzer generating stable voltage for more than 2000 h, successfully competing with the state-of-the-art reference but with one tenth of Pt mass loading. Overall, this work presents an unprecedently efficient HER catalyst and opens up avenues for PtNW/SWNT catalyzing other high-impact reactions.
Highlights
A major technological obstacle with the spread of solar and wind energy is its storage for cloudy and windless occasions
We present a robust and upscalable three-step synthesis for preparing an unprecedented hydrogen evolution reaction (HER) electrocatalyst with an ultralow Pt loading (340 ng cm−2) on singlewalled carbon nanotubes (SWNTs)
The ozone pre-treatment of the SWNTs results in shorter platinum nanowires (PtNWs) and improved electrocatalytic efficiency compared with a non-ozonized counterpart
Summary
A major technological obstacle with the spread of solar and wind energy is its storage for cloudy and windless occasions. Power-to-gas energy storage via water electrolysis is one of the few options for storing excess renewable energy at large scales and over long time periods. In this process, electrical power is converted to chemical energy in the form of hydrogen. Decreasing the amount of the PGMs is important for laying the groundwork for the large-scale and long-term deployment of H2 fuel This has driven research into nonnoble metal alternatives such as transition metal phosphides [6,7], carbides [8] and nitrides [9,10] or chalcogenides [11,12,13]. Pt-based HER catalysts are still regarded as the most relevant starting point owing to their better overall performance in activity, stability and integrability to industrial applications such as PEM electrolyzers in acidic environment [14,15]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
