General synthesis of single atom electrocatalysts via a facile condensation–carbonization process

DOI: 10.1039/D0TA08115A

Authors: Weiming Chen (South China University of Technology) , Xuanli Luo (University of Nottingham) , Thomas J. A. Slater (Diamond Light Source) , Yongfang Zhou (South China University of Technology) , Sanliang Ling (University of Nottingham) , Rui Bao (Kunming University of Science and Technology) , Jesum Alves Fernandes (University of Nottingham) , Jianshe Wang (Zhengzhou University) , Yi Shen (South China University of Technology; Overseas Expertise Introduction Center for Discipline Innovation of Food Nutrition and Human Health (111 Center))
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Materials Chemistry A , VOL 355

State: Published (Approved)
Published: November 2020
Diamond Proposal Number(s): 23723 , 17198

Abstract: The general and cost-effective synthesis of single atom electrocatalysts (SAECs) still remains a great challenge. Herein, we report a general synthetic protocol for the synthesis of SAECs via a simple condensation–carbonization process, in which furfural and cyanamide were condensation polymerized in the presence of polystyrene nanospheres and metal ions, followed by a pyrolysis to N-doped carbon nanosheet (NCNS) supported SAECs. Six types of SAECs containing platinum, palladium, gold, nickel, cobalt and iron were synthesized to demonstrate the generality of the synthesis protocol. This methodology affords a facile solution to the trade-off between support conductivity and metal loading of SAECs by optimizing the ratio of carbon/nitrogen precursors, i.e., furfural and cyanamide. The presence of single metal atoms was confirmed by high-angle annular dark field scanning transmission electron microscopy and X-ray absorption fine structure measurements. The three-dimensional distribution of single platinum atoms was vividly revealed by depth profile analysis using a scanning transmission electron microscope. The resulting SAECs showed excellent performance for glycerol electro-oxidation and water splitting in alkaline solutions. Notably, Pt/NCNSs possessed an unprecedent mass-normalized current density of 5.3 A per milligram of platinum, which is 32 times that of the commercial Pt/C catalyst. Density functional theory calculations were conducted to reveal the adsorption behavior of glycerol over the SAECs. Using Ni/NCNSs and Co/NCNSs as anodic and cathodic electrocatalysts, we constructed a solar panel powered electrolytic cell for overall water splitting, leading to an overall energy efficiency of 8.8%, which is among the largest solar-to-hydrogen conversion efficiencies reported in the literature.

Diamond Keywords: Photovoltaics

Subject Areas: Chemistry, Materials, Energy

Diamond Offline Facilities: Electron Physical Sciences Imaging Centre (ePSIC)
Instruments: B18-Core EXAFS , E01-JEM ARM 200CF

Added On: 15/12/2020 14:39

Discipline Tags:

Energy Storage Energy Physical Chemistry Catalysis Energy Materials Chemistry Materials Science

Technical Tags:

Microscopy Spectroscopy Electron Microscopy (EM) Transmission Electron Microscopy (TEM) X-ray Absorption Spectroscopy (XAS)