Engineering the Low Coordinated Pt Single Atom to Achieve the Superior Electrocatalytic Performance toward Oxygen Reduction. Issue 43 (4th October 2020)

• Record Type: Journal Article
• Authors: Song, Zhongxin; Zhu, Ya‐Nan; Liu, Hanshuo; Banis, Mohammad Norouzi; Zhang, Lei; Li, Junjie; Doyle‐Davis, Kieran; Li, Ruying; Sham, Tsun‐Kong; Yang, Lijun; Young, Alan; Botton, Gianluigi A.; Liu, Li‐Min; Sun, Xueliang
• Is Part Of: Small. Volume 16:Issue 43(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-10-04
• Subjects: atomic layer deposition -- density functional theory -- metal–organic frameworks -- oxygen reduction reaction -- single‐atom catalysts; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202003096
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Configuring metal single‐atom catalysts (SACs) with high electrocatalytic activity and stability is one efficient strategy in achieving the cost‐competitive catalyst for fuel cells' applications. Herein, the atomic layer deposition (ALD) strategy for synthesis of Pt SACs on the metal–organic framework (MOF)‐derived N‐doped carbon (NC) is proposed. Through adjusting the ALD exposure time of the Pt precursor, the size‐controlled Pt catalysts, from Pt single atoms to subclusters and nanoparticles, are prepared on MOF‐NC support. X‐ray absorption fine structure spectra determine the increased electron vacancy in Pt SACs and indicate the Pt–N coordination in the as‐prepared Pt SACs. Benefiting from the low‐coordination environment and anchoring interaction between Pt atoms and nitrogen‐doping sites from MOF‐NC support, the Pt SACs deliver an enhanced activity and stability with 6.5 times higher mass activity than that of Pt nanoparticle catalysts in boosting the oxygen reduction reaction (ORR). Density functional theory calculations indicate that Pt single atoms prefer to be anchored by the pyridinic N‐doped carbon sites. Importantly, it is revealed that the electronic structure of Pt SAs can be adjusted by adsorption of hydroxyl and oxygen, which greatly lowers free energy change for the rate‐determining step and enhances the activity of Pt SACs toward the ORR. Abstract : The atomic layer deposition (ALD) strategy for synthesis of Pt single‐atom catalysts (SACs) on the metal–organic framework (MOF)‐derived N‐doped carbon (NC) is proposed. Benefiting from the low‐coordination environment and anchoring interaction between Pt atoms and nitrogen‐doping sites from MOF‐NC support, the ALDPt SACs deliver an enhanced activity and stability in boosting the oxygen reduction reaction (ORR).